Package 'Rfast'

Title: A Collection of Efficient and Extremely Fast R Functions
Description: A collection of fast (utility) functions for data analysis. Column and row wise means, medians, variances, minimums, maximums, many t, F and G-square tests, many regressions (normal, logistic, Poisson), are some of the many fast functions. References: a) Tsagris M., Papadakis M. (2018). Taking R to its limits: 70+ tips. PeerJ Preprints 6:e26605v1 <doi:10.7287/peerj.preprints.26605v1>. b) Tsagris M. and Papadakis M. (2018). Forward regression in R: from the extreme slow to the extreme fast. Journal of Data Science, 16(4): 771--780. <doi:10.6339/JDS.201810_16(4).00006>. c) Chatzipantsiou C., Dimitriadis M., Papadakis M. and Tsagris M. (2020). Extremely Efficient Permutation and Bootstrap Hypothesis Tests Using Hypothesis Tests Using R. Journal of Modern Applied Statistical Methods, 18(2), eP2898. <doi:10.48550/arXiv.1806.10947>.
Authors: Manos Papadakis [aut, cre, cph], Michail Tsagris [aut], Marios Dimitriadis [ctb], Stefanos Fafalios [aut], Ioannis Tsamardinos [ctb], Matteo Fasiolo [ctb], Giorgos Borboudakis [ctb], John Burkardt [ctb], Changliang Zou [ctb], Kleanthi Lakiotaki [ctb], Christina Chatzipantsiou [ctb]
Maintainer: Manos Papadakis <[email protected]>
License: GPL (>= 2.0)Config/pak/sysreqs: make
Version: 2.1.0
Built: 2024-11-11 06:38:14 UTC
Source: https://github.com/rfastofficial/rfast

Help Index


Check if any column or row is fill with values

Description

Check if any column or row is fill with values.

Usage

colrow.value(x,value=0)

Arguments

x

A vector with data.

value

A value to check.

Details

Check all the column if any has all its elements equal to argument value. If found, return "TRUE". Otherwise continues with rows. If columns and rows hasn't any value vector then return "FALSE". Even if it returns "FALSE" that doesn't mean the determinant can't be value. It might be but if check before and found any value vector then for sure the determinant it'll be value.

Value

A boolean value, "TRUE" if any column OR row is all filled with value. "FALSE" otherwise.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowFalse, nth, colrange, colMedians, colVars, colSort, rowSort, rowTrue

Examples

x <- matrix(runif(10*10),10,10)
res<-colrow.value(x) 

x<-NULL

Deep copy

Description

Deep copy.

Usage

env.copy(x,all.names=FALSE)

Arguments

x

An environment object.

all.names

An logical value (TRUE or FALSE). Copy all the hidden variables or not.

Details

Deep copy of the environment object.

Value

A copy of the first argument.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans, read.directory

Examples

x <- new.env()
x$imaginary <- NULL
x$real <- NULL

# you can library the package and just press x and R will understand 
# and search automatically for a function to print the environment
x

y <- env.copy(x)

x$real <- 10

x$real == y$real # FALSE

Design Matrix

Description

Design Matrix.

Usage

design_matrix(x, ones = TRUE)

Arguments

x

A character vector or a factor type vector or a dataframe. Do not supply a numerical vector.

ones

A boolean variable specifying whether to include the ones in the design matrix or not. The default value is TRUE.

Details

This function implements the R's "model.matrix" function and is used only when the x is a factor/charactervector or Dataframe.

Value

Returns the same matrix with model.matrix.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

model.matrix

Examples

a <- design_matrix( iris[, 5] )
b <- model.matrix( ~ iris[,5] )  ## R's built-in function
all.equal(as.vector(a),as.vector(b)) ## true

a<-b<-NULL

Insert/remove function names in/from the NAMESPACE file

Description

Insert/remove function names in/from the NAMESPACE file.

Usage

AddToNamespace(path.namespace,path.rfolder)
RemoveFromNamespace(path.namespace,files.to.remove)

Arguments

path.namespace

An full path to the NAMESPACE file.

path.rfolder

An full path to the directory the new files to be added are stored.

files.to.remove

An character with the names of the functions to be removed from file NAMESPACE.

Details

AddToNameSpace: Reads the files that are exported in NAMESPACE and the functions that are inside rfolder (where R files are) and insert every function that is not exported. For that you must add the attribute "#[export]" above every function you wish to export. Also you can use the attribute "#[export s3]" for exporting S3methods. Finally, if you don't want the program to read a file just add at the top of the file the attribute "#[dont read]".

RemoveFromNamespace: Remove every function, from argument "files.to.remove", from NAMESPACE.

Value

AddToNameSpace:

without export

A character vector with the names of the R functions that don't have te "#[export]" attribute.

hidden functions

A character vector with the names of the R functions that are hidden.

RemoveFromNamespace: Return the files that could not be removed.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans, read.directory

Examples

## Not run: 
	#for example: path.namespace="C:\some_file\NAMESPACE" where is NAMESPACE file
	#path.rfolder="C:\some_file\R\" where is R files are
	#system.time( a<-AddToNamespace(path.namespace,path.rfolder) )
	#if(length(a)==0){
	#	print("all the files are inserted")
	#}else{
	#	print("The new files that inserted are: \n")
	#	a
	#}
	#system.time( a<-RemoveFromNamespace(path.namespace,c("a","b")) )
	#if(length(a)==0){
	#	print("all the files are inserted")
	#}else{
	#	print("The files thatcould not be deleted are: \n")
	#	a
	#}

## End(Not run)

Lower and Upper triangular of a matrix

Description

Lower/upper triangular matrix.

Usage

lower_tri(x, suma = FALSE, diag = FALSE)
upper_tri(x, suma = FALSE, diag = FALSE)
lower_tri.assign(x, v, diag = FALSE)
upper_tri.assign(x, v, diag = FALSE)

Arguments

x

A matrix with data or a vector with 2 values which is the dimension of the logical matrix to be returned with the upper or lower triangular filled with "TRUE".

v

A numeric vector for assign to the lower/upper triangular.

suma

A logical value for returning the sum of the upper or lower triangular. By default is "FALSE". Works only if argument "x" is matrix.

diag

A logical value include the diagonal to the result.

Value

Get a lower/upper triangular logical matrix with values TRUE/FALSE, a vector with the values of a lower/upper triangular, the sum of the upper/lower triangular if suma is set TRUE or assign to the lower/upper (only for large matrices) triangular. You can also include diagonal with any operation if argument diag is set to "TRUE".

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, colFalse, nth, rowrange, rowMedians, rowVars, colTrue

Examples

x <- matrix(runif(10*10),10,10)

all.equal(lower_tri(c(10,10)),lower.tri(x))

all.equal(lower_tri(x),x[lower.tri(x)])

#all.equal(upper_tri(c(10,10)),upper.tri(x))

#all.equal(upper_tri(x),x[upper.tri(x)])



#all.equal(lower_tri(c(10,10),diag = TRUE),lower.tri(x,diag = TRUE))

#all.equal(lower_tri(x,diag = TRUE),x[lower.tri(x,diag = TRUE)])

#all.equal(upper_tri(c(10,10),diag = TRUE),upper.tri(x,diag = TRUE))

#all.equal(upper_tri(x,diag = TRUE),x[upper.tri(x,diag = TRUE)])

all.equal(lower_tri.assign(x,diag = TRUE,v=rep(1,1000)),x[lower.tri(x,diag = TRUE)]<-1)

all.equal(upper_tri.assign(x,diag = TRUE,v=rep(1,1000)),x[upper.tri(x,diag = TRUE)]<-1)

x<-NULL

Match

Description

Return the positions of its first argument that matches in its second.

Usage

Match(x,key=NULL)

Arguments

x

A numeric vector.

key

The value/vector for searching in vector x. For now let it NULL. dont't use it!.

Details

This function implements the R's \"match\" function. This version basicaly calculates the match(x,sort(unique(x))) for now. Do not use the argument key!

Value

Returns the position/positions of the given key/keys in the x vector.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

match

Examples

y <- rnorm(100)
a <- Match(y)
b <-50
all.equal(as.vector(a),as.vector(b))

Permutation

Description

Permute the given vector.

Usage

permutation(x, nperm = gamma(length(x)+1))
permutation.next(x, nperm = gamma(length(x)+1))
permutation.prev(x, nperm = gamma(length(x)+1))
bincomb(n)

Arguments

x

A numeric vector with data.

nperm

An integer value for returning specific number of combinations. By defualt is set to all combinations. Must be between 0<=nperm<=gamma(length(x)+1)

n

An integer value for the length of the binary number.

Details

This function implements "Permutation", which means all the possible combinations. In the permutation.next and permutation.prev if there aren't possible combinations it returns the same vector. "Binary Combinations" for "bincomb", means all the possible combinations for the binary number with length "n".

Value

Returns a matrix with all possible combinations of the given vector or a matrix row with one possible combinations.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

combn,comb_n

Examples

y <- rnorm(3)
b <- permutation(y)
b <- permutation.next(y)
b <- permutation.prev(y)
g <- bincomb(3)

Replicate columns/rows

Description

Replicate columns/rows.

Usage

rep_col(x,n)
rep_row(x,n)

Arguments

x

A vector with data.

n

Number of new columns/rows.

Value

A matrix where each column/row is equal to "x".

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowFalse, nth, colrange, colMedians, colVars, colSort, rowSort, rowTrue

Examples

x <- runif(10)
all.equal(rep_col(x,10),matrix(x,nrow=length(x),ncol=10))
all.equal(rep_row(x,10),matrix(x,ncol=length(x),nrow=10,byrow=TRUE))

Represantation of Stack

Description

Represantation of Stack.

Usage

Stack(x,type=NULL)

Arguments

x

Any type that could be convert to vector or an integer value.

type

A type for the Stack, "integer", "numeric" or any other that accepts one argument.

Details

Stack is an abstract data type - data structure based on the principle of last in first out. To access the 3 fields, use operator "$".

Value

An object of class "Stack". This object holds 3 fields:

pop: remove the first element (from the top). top: access the first element (from the top). push: add an element to the top of the Stack.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans, read.directory

Examples

x<-Stack(10,type=integer)

x$push(5)
x$push(10)
x$top()  == 10
x$pop()
x$top() == 5

y<-rnorm(10)
x<-Stack(x)

x$push(5) # length increased to 11
x$top() # access the last element that pushed, 5
x$pop() # pop the last element that pushed

Sort and unique

Description

Sort and unique numbers.

Usage

sort_unique(x)
sort_unique.length(x)

Arguments

x

A numeric vector.

Details

The "sort_unique" function implements R's "unique" function using C++'s function but also sort the result. The "sort_unique.length" returns the length of the unique numbers only for itegers.

Value

Returns the discrete values but sorted or their length (depending on the function you do).

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

colSort, rowSort, sort_cor_vectors

Examples

y <- rnorm(100)
a <- sort_unique(y)
b <- sort.int(unique(y))
all.equal(as.vector(a),as.vector(b))
x <- rpois(1000,10)
sort_unique.length(x)
length(sort_unique(x))

x<-a<-b<-NULL

A Collection of Efficient and Extremely Fast R Functions

Description

A collection of fast (utility) functions for data analysis. Column and row wise means, medians, variances, minimums, maximums, many t, F and G-square tests, many regressions (normal, logistic, Poisson), are some of the many fast functions. References: a) Tsagris M., Papadakis M. (2018). Taking R to its limits: 70+ tips. PeerJ Preprints 6:e26605v1 <doi:10.7287/peerj.preprints.26605v1>. b) Tsagris M. and Papadakis M. (2018). Forward regression in R: from the extreme slow to the extreme fast. Journal of Data Science, 16(4): 771–780. <doi:10.6339/JDS.201810_16(4).00006>. c) Chatzipantsiou C., Dimitriadis M., Papadakis M. and Tsagris M. (2020). Extremely Efficient Permutation and Bootstrap Hypothesis Tests Using Hypothesis Tests Using R. Journal of Modern Applied Statistical Methods, 18(2), eP2898. <doi:10.48550/arXiv.1806.10947>.

Details

Package: Rfast
Type: Package
Version: 2.1.0
Date: 2023-11-08
License: GPL (>= 2.0)Config/pak/sysreqs: make

Maintainers

Manos Papadakis <[email protected]>

Note

Acknowledgments: We would like to acknowledge:

  • Professor Kurt Hornik, Doctor Uwe Ligges (and the rest of R core team) for their invaluable help with this R package.

  • Erich Studerus for his invaluable comments.

  • Neal Fultz for his suggestions.

  • Vassilis Vasdekis for his invaluable help with the random effects models.

  • Marios Dimitriadis' work was funded by the Special Account for Research Funds of the University of Crete, Department of Computer Science.

  • Phillip Si is greatly acknowledged for his help with the Floyd-Warshal algorithm.

  • Keefe Murphy for his invaluable help with NEWS file and for his suggestions.

  • Zacharias Papadovassilakis gave us the inspiration for the memory efficient version of the k-NN algorithm.

  • Yannis Pantazis explained us how the orhtogonal matching pursuit works.

  • Achim Zeileis for his help with the quasi Poisson regression models.

  • Pedro J. Aphalo for finding a bug.

  • Dimitris Kyriakis for finding a bug.

  • Cyrille Conord for finding a bug.

  • Aaron Robotham for finding a bug.

  • Calvin Pan from the Department of Human Genetics at UCLA found a bug in the function glm_logistic and he is greatly acknowledged for that.

  • Adam Muschielok from Rodenstock GmbH found a bug in the function vmf.mle and he is greatly acknowledged for that.

  • Bret Presnell for detecting and correcting a bug in the function rvmf.

  • Gabriel Hoffman for spotting a mistake in the fuction dirimultinom.mle.

  • Lutz von der Burchard for spotting a bug in the function bic.corfsreg.

Author(s)


All k possible combinations from n elements

Description

All k possible combinations from n elements.

Usage

comb_n(n, k,simplify=TRUE)

Arguments

n

A positive INTEGER number or a vector with numbers.

k

A positive integer number at most equal to n or at most equal to the length of n, if n is a vector.

simplify

A logical value for return List instead of matrix.

Value

A matrix with k columns and rows equal to the number of possible unique combinations of n with k elements. If simplify is set to TRUE then a list with k values where each value has length equal to the number of possible unique combinations of n with k elements.

Author(s)

Manos Papadakis and Marios Dimitriadis

R implementation and documentation: Manos Papadakis <[email protected]> and Marios Dimitriadis <[email protected]>.

References

Nijenhuis A. and Wilf H.S. (1978). Combinatorial Algorithms for Computers and Calculators. Academic Press, NY.

See Also

nth, colMaxs, colMins, colrange

Examples

comb_n(20, 4)
combn(20, 4)
x <- rnorm(5)
res<-comb_n(x, 3)

Analysis of covariance

Description

Analysis of covariance

Usage

ancova1(y, ina, x, logged = FALSE)

Arguments

y

A numerical vector with the data, the response variable.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero.

x

A numerical vector whose length is equal to the number of rows of y. This is the covariate.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

Analysis of covariance is performed. No interaction between the factor and the covariate is tested. Only the main effects. The design need not be balanced. The values of ina need not have the same frequency. The sums of squares have been adjusted to accept balanced and unbalanced designs.

Value

A matrix with the test statistic and the p-value for the factor variable and the covariate.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

D.C. Montgomery (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons

See Also

ancovas, ftests, ttests, anova1

Examples

y <- rnorm(90)
ina <- rbinom(90, 2, 0.5) + 1
x <- rnorm(90)
a <- ancova1(y, ina, x)

Analysis of variance with a count variable

Description

Analysis of variance with a count variable.

Usage

poisson.anova(y, ina, logged = FALSE)
geom.anova(y, ina, type = 1, logged = FALSE)
quasipoisson.anova(y, ina, logged = FALSE)

Arguments

y

A numerical vector with discrete valued data, i.e. counts.

ina

A numerical vector with discrete numbers starting from 1, i.e. 1, 2, 3, 4,... or a factor variable. This is suppose to be a categorical predictor. If you supply a continuous valued vector the function will obviously provide wrong results.

type

This argument is for the geometric distribution. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

This is the analysis of variance with Poisson or geometric distributed data. What we do is a log-likelihood ratio test. However, this is exactly the same as Poisson regression with a single predictor variable who happens to be categorical. Needless to say that this is faster function than the glm command in R. For the same purpose with a Bernoulli variable use g2Test. The quasinpoisson.anova is when in the glm function you specify family = quasipoisson. This is suitable for the case of over or under-dispersed data.

Value

A vector with two values, the difference in the deviances (or the scale difference in the case of quasi poisson) and the relevant p-value. The quasipoisson.anova also returns the estimate of the ϕ\phi parameter.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

logistic.cat1, g2Test, poisson.anovas, anova, poisson_only, poisson.mle

Examples

y <- rpois(300, 10)
ina <- rbinom(300, 3, 0.5) + 1 
a1 <- poisson.anova(y, ina) 
a2 <- glm(y ~ ina, poisson) 


res<-anova(a2, test = "Chisq")

y <- rgeom(300, 0.7)
res<-geom.anova(y, ina)

Angular central Gaussian random values simulation

Description

Angular central Gaussian random values simulation.

Usage

racg(n, sigma, seed = NULL)

Arguments

n

The sample size, a numerical value.

sigma

The covariance matrix in RdR^d.

seed

If you want the same to be generated again use a seed for the generator, an integer number.

Details

The algorithm uses univariate normal random values and transforms them to multivariate via a spectral decomposition. The vectors are then scaled to have unit length.

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Tyler D. E. (1987). Statistical analysis for the angular central Gaussian distribution on the sphere. Biometrika 74(3): 579-589.

See Also

acg.mle, rmvnorm, rmvlaplace, rmvt

Examples

s <- cov( iris[, 1:4] )
x <- racg(100, s)
res<-acg.mle(x)  
res<-vmf.mle(x)  ## the concentration parameter, kappa, is very low, close to zero, as expected.

ANOVA for two quasi Poisson regression models

Description

ANOVA for two quasi Poisson regression models.

Usage

anova_quasipois.reg(mod0, mod1, n)

Arguments

mod0

An object as returned by the "qpois.reg" function. This is the null model.

mod1

An object as returned by the "qpois.reg" function. This is the alternative model.

n

The sample size. This is necessary to calculate the degrees of freedom.

Details

This is an ANOVA type significance testing for two quasi Poisson models.

Value

A vector with 4 elements, the test statistic value, its associated p-value and the relevant degrees of freedom of the numerator and the denominator.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Papke L. E. & Wooldridge J. (1996). Econometric methods for fractional response variables with an application to 401(K) plan participation rates. Journal of Applied Econometrics, 11(6): 619–632.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

anova_qpois.reg, qpois.reg, univglms, quasipoisson.anova

Examples

y <- rnbinom(200, 10, 0.5)
x <- matrix(rnorm(200 * 3), ncol = 3)
a1 <- qpois.reg(x, y)
a0 <- qpois.reg(x[, 1], y)
res<-anova_quasipois.reg(a0, a1, 200)
b1 <- glm(y ~ x, family = quasipoisson)
b0 <- glm(y ~ x[, 1], family = quasipoisson)
res<-anova(b0, b1, test = "F")
c1 <- glm(y ~ x, family = poisson)
c0 <- glm(y ~ x[, 1], family = poisson)
res<-anova(c0, c1, test = "Chisq")

Apply method to Positive and Negative number

Description

Apply method to Positive and Negative number.

Usage

negative(x,method = "min")
positive(x,method = "min")
positive.negative(x,method = "min")

Arguments

x

A numerical vector with data.

method

Accept 3 values. "min", "max", "min.max".

Details

These functions apply the chosen method to the chosen subset (negative, positive, or both) from the vector and return the result.

Value

negative: apply the chosen method to every negative number of the input vector. positive: apply the chosen method to every positive number of the input vector. positive.negative: apply the chosen method to every negative and positive number of the input vector.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

nth, colnth, rownth,sort_unique, Round

Examples

x <- rnorm(1000)

identical(negative(x,"min"), min(x<0))
identical(positive(x,"min"), min(x>0))
identical(positive.negative(x,"min"), c(min(x<0),min(x>0)))

x<-NULL

Apply to each column a method under condition

Description

Apply to each column a method under condition.

Usage

apply.condition(x,method = "+",oper = ">",cond.val = 0)

Arguments

x

An integer matrix.

method

One of: "+", "-", "*", "min", "max".

oper

One of: ">, "<", ">=", "<=".

cond.val

An integer value for the condition.

Details

Apply to each col the specified method using the condition.

Value

An integer vector with the coresponding values.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

See Also

colsums, colMedians, colVars

Examples

x <- matrix(rpois(100,6),10, 10)
identical(apply(x,2,function(x){ sum(x[x>0]) }), apply.condition(x,"+",">",0))
x<-NULL

Backward selection regression

Description

Backward selection regression.

Usage

bs.reg(y, x, alpha = 0.05, type = "logistic")

Arguments

y

A numerical vector with the response variable values. It can either be of 0 and 1 values (Logistic regression) or of integer values 0, 1, 2,... (Poisson regression).

x

A numerical matrix with the candidate variables.

alpha

Threshold (suitable values are in [0,1]) for assessing the significance of p-values. The default value is at 0.05.

type

For the Logistic regression put "logistic" (default value) and for Poisson type "poisson".

Details

This function currently implements only the binary Logistic and Poisson regressions. If the sample size is less than the number of variables a notification message will appear and no backward regression will be performed.

Value

The output of the algorithm is an S3 object including:

info

A matrix with the non selected variables and their latest test statistics and p-values.

Vars

A vector with the selected variables.

Author(s)

Marios Dimitriadis

R implementation and documentation: Marios Dimitriadis <[email protected]>

See Also

fs.reg, univglms, cor.fsreg

Examples

y <- rbinom(50, 1, 0.5)
x <- matrnorm(50, 10)
res<-bs.reg(y, x)

BIC (using partial correlation) forward regression

Description

BIC (using partial correlation) forward regression.

Usage

bic.corfsreg(y, x, tol = 2)

Arguments

y

A numerical vector.

x

A matrix with data, the predictor variables.

tol

If the BIC difference between two successive models is less than the tolerance value, the variable will not enter the model.

Details

The forward regression tries one by one the variables using the F-test, basically partial F-test every time for the latest variable. This is the same as testing the significance of the coefficient of this latest enetered variable. Alternatively the correlation can be used and this case the partial correlation coefficient. There is a direct relationship between the t-test statistic and the partial correlation coefficient. Now, instead of having to calculate the test statistic, we calculate the partial correlation coefficient. The largest partial correlation indicates the candidate variable to enter the model. If the BIC of the regression model with that variable included, reduces, less than "tol" from the previous model without this variable, the variable enters.

Value

A matrix with two columns, the index of the selected variable(s) and the BIC of each model. The first line is always 0 and the BIC of the model with no predictor variables.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

See Also

cor.fsreg, score.glms, univglms, logistic_only, poisson_only, regression

Examples

## 200 variables, hence 200 univariate regressions are to be fitted
x <- matrix( rnorm(200 * 200), ncol = 200 )
y <- rnorm(200)
a1 <- bic.corfsreg(y, x)
a2 <- cor.fsreg(y, x)
x <- NULL

BIC forward regression with generalised linear models

Description

BIC forward regression with generalised linear models.

Usage

bic.fs.reg(y, x, tol = 2, type = "logistic")

Arguments

y

A numerical vector.

x

A matrix with data, the predictor variables.

tol

If the BIC difference between two successive models is less than the tolerance value, the variable will not enter the model.

type

If you have a binary dependent variable, put "logistic". If you have count data, put "poisson".

Details

The forward regression tries one by one the variables using the BIC at each step for the latest variable. If the BIC of the regression model with that variable included, is less than "tol" from the previous model without this variable, the variable enters.

Value

A matrix with two columns, the index of the selected variable(s) and the BIC of each model.

Author(s)

Marios Dimitriadis

R implementation and documentation: Marios Dimitriadis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

See Also

fs.reg, bic.corfsreg, cor.fsreg, score.glms, univglms, logistic_only, poisson_only, regression

Examples

x <- matrix(rnorm(200 * 50), ncol = 50)
## 200 variables, hence 200 univariate regressions are to be fitted
y <- rbinom(200, 1, 0.5)
a <- bic.fs.reg(y, x)
x <- NULL

Binomial coefficient and its logarithm

Description

Binomial coefficient and its logarithm.

Usage

Lchoose(x, k)
Choose(x, k)

Arguments

x

A vector with integer values numbers.

k

A positive non zero at most equal to x.

Details

The binomial coefficient or its logarithm are evaluated.

Value

A vector with the answers.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]>

See Also

comb_n, Lbeta, Lgamma

Examples

x <- sample(20:30, 100, replace = TRUE)
res<-Choose(x, 4)
res<-Lchoose(x, 4)

x<-NULL

Bootstrap t-test for 2 independent samples

Description

Bootstrap t-test for 2 independent samples.

Usage

boot.ttest2(x, y, B = 999)

Arguments

x

A numerical vector with the data.

y

A numerical vector with the data.

B

The number of bootstrap samples to use.

Details

Instead of sampling B times from each sample, we sample B\sqrt{B} from each of them and then take all pairs. Each bootstrap sample is independent of each other, hence there is no violation of the theory.

Value

A vector with the test statistic and the bootstrap p-value.

Author(s)

Michail Tsagris and Christina Chatzipantsiou

R implementation and documentation: Michail Tsagris <[email protected]> and Christina Chatzipantsiou <[email protected]>.

References

B.L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

Efron Bradley and Robert J. Tibshirani (1993). An introduction to the bootstrap. New York: Chapman & Hall/CRC.

Chatzipantsiou C., Dimitriadis M., Papadakis M. and Tsagris M. (2019). Extremely efficient permutation and bootstrap hypothesis tests using R. To appear in the Journal of Modern Applied Statistical Methods.

https://arxiv.org/ftp/arxiv/papers/1806/1806.10947.pdf

See Also

ttest2, exact.ttest2, ftest

Examples

tic <- proc.time()
x <- rexp(40, 4)
y <- rbeta(50, 2.5, 7.5)
a <- boot.ttest2(x, y, 9999)
a

Check if values are integers and convert to integer

Description

Check if values are integers and convert to integer.

Usage

is_integer(x)
as_integer(x,result.sort = TRUE,init = 1)

Arguments

x

is_integer: A vector with numeric data. as_integer: A vector with data.

result.sort

A logical value for sorting the result.

init

An integer value to start.

Details

The behavior of these functions are different than R's built in.

is_integer: check if all the values are integers in memory. If typeof is double, and the values are integers in range -2^31 : 2^31 then it is better to convert to integer vector for using less memory. Also you can decrease the time complexity.

as_integer: converts the discrete values to integers.

Value

is_integer: A logical value, TRUE if all values are integers and in range -2^31 : 2^31. Otherwise FALSE.

as_integer: By default the function will return the same result with "as.numeric" but the user can change the "init" value not start from 1 like R's. Also the result can be unsorted using "result.sort".

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

as_integer, colVars, colmeans, read.directory

Examples

x<-runif(10)
y1<-is_integer(x) # y1 is FALSE
x<-as.numeric(rpois(10,10)) # integers but typeof is double
y1<-is_integer(x) # y1 is TRUE so you can convert to integer vector.

as_integer(letters) ## as.numeric(letters) produce errors
x<-y1<-NULL

Check Namespace and Rd files

Description

Check Namespace/Rd and examples files.

Usage

checkNamespace(path.namespace,path.rfolder)
checkAliases(path.man,path.rfolder)
checkTF(path.man)
checkExamples(path.man,package,each = 1,print.errors = stderr(),
	print.names = FALSE)
checkUsage(path.man,path.rfolder)

Arguments

path.namespace

An full path to the "NAMESPACE" file.

package

A character vector with the name of the package.

path.rfolder

An full path to the directory that contains the "R" files.

path.man

An full path to the directory that contains the "Rd" files.

each

An integer value for running each example.

print.errors

Print the errors to a file. By default it's "stderr()".

print.names

A boolean value (TRUE/FALSE) for printing the names of the files before running the examples.

Details

checkNamespace: reads from the NAMESPACE folder all the export R functions, reads from folder R all the R functions and check if all the functions are export.

checkAliases: reads from the man directory all the Rd files, then reads from each file the aliases and check if:

  • All the R files has man file or an alias.

  • All aliases belongs to functions.

  • If there are dublicated aliases.

checkExamples: reads from the man directory all the Rd files, then read from each file the examples and then run each of them. If you want to print the errors in any file then set "print.errors=file_name" or in the standard error "print.errors=stderr()" and then you will see all the errors for every file. Set to argument "package" the name of your package. The argument "print.names" it is very helpful because if any of you function crashes R during running you will never know which one was. So setting it "TRUE", it will print the name of each file before running it's example.It might crash, but you will know which file. Remember that there is always an error timeout so it might didn't crash the current file but one from the previous.

checkTF: reads from the man directory all the Rd files, then read from each file the examples and checks if any examples has the values "T" and "F" instead "TRUE" and "FALSE". The "T","F" is wrong.

checkUsage: reads from the man directory all the Rd files and for each man check if the usage section has the right signature for the functions from the R directory.

checkTF, checkUsage, checkAliases: you can choose which files not to read for both R and Rd. You must add in the first line of the file in comment the "attribute" "[dont read]". Then each function will know which file to read or not. For Rd you add "%[dont read]" and for R "#[dont read]". Finally, these functions will return in the result a list of which files had this attribute.

Value

checkNamespace: a vector with the names of missing R files. (Don't use it for now)

checkAliases: a list with 4 fields.

  • Missing Man files: A vector with the names of the missing Rd files or nothing.

  • Missing R files: A vector with the names of the missing R files or nothing.

  • Duplicate alias: A vector with the names of the dublicate aliases or nothing.

  • dont read: A list with 2 fields

    • R: A character vector whith the names of the files that had attribute "#[dont read]" or nothing.

    • Rd: A character vector whith the names of the files that had attribute "%[dont read]" or nothing.

checkExamples: a list with 3 fields

  • Errors: A character vector with the names of the Rd files that produced an error.

  • Big Examples: A character vector with the names of the Rd files that has big examples per line.

  • dont read: A list with 2 fields

    • R: A character vector whith the names of the files that had attribute "#[dont read]" or nothing.

    • Rd: A character vector whith the names of the files that had attribute "%[dont read]" or nothing.

checkTF: a list with 3 fields

  • TRUE: A character vector with the names of the Rd files that has "T" or nothing.

  • FALSE: A character vector with the names of the Rd files that has "F" or nothing.

  • dont read: A list with 2 fields

    • R: A character vector whith the names of the files that had attribute "#[dont read]" or nothing.

    • Rd: A character vector whith the names of the files that had attribute "%[dont read]" or nothing.

checkUsage: a list with 3 fields

  • missing functions: A character vector with the name of the file that is missing and the Rd file that is found or nothing.

  • missmatch functions: A character vector with the name of the file that has missmatch function and the Rd file that is found or nothing.

  • dont read: A list with 2 fields

    • R: A character vector whith the names of the files that had attribute "#[dont read]" or nothing.

    • Rd: A character vector whith the names of the files that had attribute "%[dont read]" or nothing.

  • hidden functions: A character vector with the name of the functions thath have been declared as hidden.

  • usage lines wider than 90 characters: A list with the Rd's that have usages that are wider than 90 characters.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

read.directory, AddToNamespace, sourceR, sourceRd, read.examples

Examples

#for example: path.namespace="C:\some_file\NAMESPACE"
	#for example: path.rfolder="C:\some_file\R\"
	#for example: path.man="C:\some_file\man\"
	#system.time( a<-checkNamespace(path.namespace,path.rfolder) )
	#system.time( b<-checkAliases(path.man,path.rfolder) )
	#system.time( b<-checkExamples(path.man) )
	#system.time( b<-checkExamples(path.man,2) )
	#system.time( b<-checkTF(path.man) )
	#system.time( b<-checkTF(path.man,path.rfolder) )

Check whether a square matrix is symmetric

Description

Check whether a square matrix is symmetric.

Usage

is.symmetric(x)

Arguments

x

A square matrix with data.

Details

Instead of going through the whole matrix, the function will stop if the first disagreement is met.

Value

A boolean value, TRUE of FALSE.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

cholesky, cora, cova

Examples

x <-matrix( rnorm( 100 * 400), ncol = 400 )
s1 <- cor(x)
is.symmetric(s1)
x <- x[1:100, ]
is.symmetric(x)

x<-s1<-NULL

Chi-square and G-square tests of (unconditional) indepdence

Description

Chi-square and G-square tests of (unconditional) indepdence.

Usage

gchi2Test(x, y, logged = FALSE)

Arguments

x

A numerical vector or a factor variable with data. The data must be consecutive numbers.

y

A numerical vector or a factor variable with data. The data must be consecutive numbers.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The function calculates the test statistic of the χ2\chi^2 and the G2G^2 tests of unconditional independence between x and y. x and y need not be numerical vectors like in g2Test. This function is more close to the spirit of MASS' loglm function which calculates both statistics using Poisson log-linear models (Tsagris, 2017).

Value

A matrix with two rows. In each row the X2 or G2 test statistic, its p-value and the degrees of freedom are returned.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

References

Tsagris M. (2017). Conditional independence test for categorical data using Poisson log-linear model. Journal of Data Science, 15(2):347-356.

See Also

g2Test_univariate, g2Test_univariate_perm, g2Test

Examples

nvalues <- 3
nvars <- 2
nsamples <- 5000
data <- matrix( sample( 0:(nvalues - 1), nvars * nsamples, replace = TRUE ), nsamples, nvars )

res<-gchi2Test(data[, 1], data[, 2])
res<-g2Test_univariate( data, rep(3, 2) )  ## G^2 test
res<-chisq.test(data[, 1], data[, 2])  ## X^2 test from R
  
data<-NULL

Cholesky decomposition of a square matrix

Description

Cholesky decomposition of a square matrix.

Usage

cholesky(x,parallel = FALSE)

Arguments

x

A square positive definite matrix.

parallel

A boolean value for parallel version.

Details

The Cholesky decomposition of a square positive definite matrix is computed. The use of parallel is suggested for matrices with dimensions of 1000 or more.

Value

An upper triangular matrix.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

See Also

is.symmetric

Examples

x = matrix(rnorm(1000 * 50), ncol = 50)
s = cov(x)
a1 <- cholesky(s)
#a2 <- chol(s)
#all.equal(a1[upper.tri(a1)], a2[upper.tri(a2)])
x <- NULL
s <- NULL
a1 <- NULL
a2 <- NULL

Circular or angular regression

Description

Regression with circular dependent variable and Euclidean or categorical independent variables.

Usage

spml.reg(y, x, tol = 1e-07, seb = FALSE, maxiters = 100)

Arguments

y

The dependent variable, it can be a numerical vector with data expressed in radians or it can be a matrix with two columns, the cosinus and the sinus of the circular data. The benefit of the matrix is that if the function is to be called multiple times with the same response, there is no need to transform the vector every time into a matrix.

x

The independent variable(s). Can be Euclidean or categorical (factor variables).

tol

The tolerance value to terminatate the Newton-Raphson algorithm.

seb

Do you want the standard error of the estimates to be returned? TRUE or FALSE.

maxiters

The maximum number of iterations to implement.

Details

The Newton-Raphson algorithm is fitted in this regression as described in Presnell et al. (1998).

Value

A list including:

iters

The number of iterations required until convergence of the EM algorithm.

be

The regression coefficients.

seb

The standard errors of the coefficients.

loglik

The value of the maximised log-likelihood.

seb

The covariance matrix of the beta values.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Presnell Brett, Morrison Scott P. and Littell Ramon C. (1998). Projected multivariate linear models for directional data. Journal of the American Statistical Association, 93(443): 1068-1077.

See Also

spml.mle, iag.mle, acg.mle

Examples

x <- rnorm(100)
z <- cbind(3 + 2 * x, 1 -3 * x)
y <- cbind( rnorm(100,z[ ,1], 1), rnorm(100, z[ ,2], 1) )
y <- y / sqrt( rowsums(y^2) )
a1 <- spml.reg(y, x)
y <- atan( y[, 2] / y[, 1] ) + pi * I(y[, 1] < 0) 
a2 <- spml.reg(y, x)

Circular-linear correlation

Description

It calculates the squared correlation between a circular and one or more linear variables.

Usage

circlin.cor(theta, x)

Arguments

theta

A circular variable expressed in radians.

x

The linear variable or a matrix containing many linear variables.

Details

The squared correlation between a circular and one or more linear variables is calculated.

Value

A matrix with as many rows as linear variables including:

R-squared

The value of the squared correlation.

p-value

The p-value of the zero correlation hypothesis testing.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Mardia, K. V. and Jupp, P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.

See Also

spml.reg

Examples

phi <- rvonmises(50, 2, 20, rads = TRUE)
x <- 2 * phi + rnorm(50)
y <- matrix(rnorm(50 * 5), ncol = 5)
res<-circlin.cor(phi, x)
res<-circlin.cor(phi, y)
y <- NULL

Coefficient matrices.

Description

Coefficient matrices.

Usage

coeff(x, method,vector = FALSE)

Arguments

x

A matrix with data. The distances will be calculated between pairs of rows. In the case of vecdist this is a vector. For the haversine distance it must be a matrix with two columns, the first column is the latitude and the second the longitude.

method

See details for the available methods.

vector

For return a vector instead a matrix.

Details

  • bhattacharyya : (PiQi)\sum \sqrt(P_i * Q_i)

Value

A square matrix with the pairwise coefficients.

Author(s)

Manos Papadakis.

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

dista, Dist

Examples

x <- matrix(rnorm(50 * 10), ncol = 10)
a1 <- coeff(x,"bhattacharyya")
x<-a1<-NULL

Colum-wise cumulative operations (sum, prod, min, max)

Description

Colum-wise cumulative operations (sum, prod, min, max).

Usage

colCumSums(x)
colCumProds(x)
colCumMins(x)
colCumMaxs(x)

Arguments

x

A numerical matrix.

Details

Cumulative mins, maxs, sums and prods are returned.

Value

A matrix with the results. It has one row less than the initial matrix.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

See Also

colsums, colMedians, colVars

Examples

x <- matrnorm(10, 10)
res<-colCumSums(x)
res<-colCumMins(x)
res<-colCumMaxs(x)
res<-colCumProds(x)

Column and row wise coefficients of variation

Description

Column and row wise coefficients of variation.

Usage

colcvs(x, ln = FALSE, unbiased = FALSE) 
rowcvs(x, ln = FALSE, unbiased = FALSE)

Arguments

x

A numerical matrix with the data.

ln

If you have log-normally distributed data (or assume you do), then set this to TRUE.

unbiased

A boolean variable indicating whether the unbiased for shpould be returned. This is applicable in case of small samples.

Details

The colum-wise coefficients of variation are calculated.

Value

A vector with the coefficient of variation for each column or row.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colsums, colVars

Examples

m <- rnorm(100, 10)
x <- matrix(rnorm(100 * 100, m, 1), ncol = 100)
a1 <- colcvs(x)
a2 <- colcvs(x[1:25, ], unbiased = TRUE)
a3 <- colcvs( exp(x), ln = TRUE)
x <- NULL

Column and row-wise Any

Description

Column and row-wise Any/All of a matrix.

Usage

colAny(x)
rowAny(x)
colAll(x, parallel = FALSE, cores = 0)
rowAll(x, parallel = FALSE, cores = 0)

Arguments

x

A logical matrix with the data.

parallel

Do you want the computations to take place in parallel? The default value is FALSE.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

The functions is written in C++ in order to be as fast as possible.

Value

A vector where item "i" is true if found Any/All true in column/row "i". Otherwise false.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Median, colMedians, colMeans (buit-in R function)

Examples

x <- matrix(as.logical(rbinom(100*100,1,0.5)),100,100)
a<-colAny(x)
#b<-apply(x,2,any)
#all.equal(a,b)

a<-rowAny(x)
#b<-apply(x,1,any)
#all.equal(a,b)

a<-colAll(x)
#b<-apply(x,2,all)
#all.equal(a,b)

a<-b<-x<-NULL

Column and row-wise means of a matrix

Description

Column and row-wise means of a matrix.

Usage

colmeans(x, parallel = FALSE, cores = 0)
## S3 method for class 'matrix'
colmeans(x, parallel = FALSE, cores = 0)
## S3 method for class 'data.frame'
colmeans(x, parallel = FALSE, cores = 0)
rowmeans(x)
colhameans(x, parallel = FALSE)
rowhameans(x)

Arguments

x

A numerical matrix or data.frame with data.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Value

A vector with the column or row arithmetic or harmonic means.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colsums, rowsums, colMins, colMedians, colMads

Examples

x <- matrix(rpois(100 * 100, 10),ncol = 100)
x1 <- colmeans(x)
#x2 <- colMeans(x)
#all.equal(x1,x2)

x1 <- rowmeans(x)
#x2 <- rowMeans(x)
#all.equal(x1,x2)

colhameans(x)
rowhameans(x) 

x<-x1<-x2<-NULL

Column and row-wise medians of a matrix or median of a vector.

Description

Column and row-wise medians of a matrix or median of a vector.

Usage

colMedians(x,na.rm = FALSE, parallel = FALSE, cores = 0)
rowMedians(x,na.rm = FALSE, parallel = FALSE, cores = 0)
Median(x,na.rm=FALSE)
med(x,na.rm=FALSE)

Arguments

x

A vector, matrix or data.frame with the data.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE.

na.rm

TRUE or FAlSE for remove NAs if exists.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

The functions is written in C++ in order to be as fast as possible.

Value

A vector with the column medians.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Median, colVars, colMeans (buit-in R function)

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
a <- apply(x, 2, median) 
b1 <- colMedians(x) 
all.equal(as.vector(a), b1)

x<-a<-b1<-NULL

Column and row-wise nth smallest value of a matrix/vector

Description

Column and row-wise nth smallest value of a matrix/vector.

Usage

colnth(x,elems, num.of.nths = 1,descending = FALSE,na.rm = FALSE,
	index.return = FALSE, parallel = FALSE, cores = 0)
rownth(x,elems, num.of.nths = 1,descending = FALSE,na.rm = FALSE,
	index.return = FALSE, parallel = FALSE, cores = 0)
nth(x, k, num.of.nths = 1,descending = FALSE,index.return = FALSE,na.rm = FALSE)

Arguments

x

A matrix with the data.

elems

An integer vector with the kth smallest number to be returned for each column/row.

k

The kth smallest/biggest number to be returned.

num.of.nths

The number of the returned nths. By default is 1. Not use with argument parallel, for now.

descending

A boolean value (TRUE/FALSE) for descending order (biggest number). By default is ascending (smallest number).

index.return

Return the index of the kth smallest/biggest number.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE only for col-row wise.

na.rm

TRUE or FAlSE for remove NAs if exists. Only for function "nth".

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

The functions is written in C++ in order to be as fast as possible.

Value

For "colnth" , "rownth": A vector with the column/row nth

For "nth": The nth value.

Author(s)

Manos Papadakis <[email protected]>

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

Median, colMedians, colMeans (buit-in R function)

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
elems <- sample(1:100,100,TRUE)
colnth(x,elems)
rownth(x,elems)
x <- rnorm(1000)

nth(x, 500)
#sort(x)[500]

x<-elems<-NULL

Column and row-wise Order - Sort Indices

Description

Column and row-wise Order - Sort Indices.

Usage

colOrder(x,stable=FALSE,descending=FALSE, parallel = FALSE, cores = 0)
rowOrder(x,stable=FALSE,descending=FALSE, parallel = FALSE, cores = 0)
Order(x,stable=FALSE,descending=FALSE,partial = NULL,parallel = FALSE)

Arguments

x

A matrix with numbers or a numeric/character vector.

stable

A boolean value for using a stable sorting algorithm.

descending

A boolean value (TRUE/FALSE) for sorting the vector in descending order. By default sorts the vector in ascending.

parallel

A boolean value for parallel version. For Order, this argument is supported on Windows and most of the unix.

partial

A boolean value for partial sorting.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE column - major ordering. Default value is 0 and it means the maximum supported cores.

Details

The function applies "order" in a column or row-wise fashion or Order a vector. If you want the same results as R's, then set "stable=TRUE" because "stable=FALSE" uses a sorting algorithm that it is not stable like R's sort. But it is faster to use the default. This verion is faster for large data, more than 300.

Value

For "colOrder" and "rowOrder" a matrix with integer numbers. The result is the same as apply(x, 2, order) or apply(x, 1, order).

For "Order" sort the vector and returns the indices of each element that it has before the sorting. The result is the same as order(x) but for the same exactly results set argument "stable" to "TRUE".

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colsums, coldiffs, colMedians, colprods

Examples

x <- matrix( runif(10 * 10), ncol = 10 )
res<-colOrder(x)
res<-apply(x, 2, order)
res<-rowOrder(x)
t(apply(x, 1, order))

y <- rnorm(100)
b <- Order(y)
a <- order(y)
all.equal(a,b) ## false because it is not stable
b <- Order(y,stable=TRUE)
all.equal(a,b) ## true because it is stable

x<-y<-b<-a<-NULL

Column and row-wise products

Description

Column and row-wise products.

Usage

colprods(x, method = "direct")
rowprods(x)

Arguments

x

A matrix with numbers.

method

The type of colCumProds to use. For direct multiplication use "direct" or "expsumlog" for a more numerically stable, but slower way.

Details

The product of the numbers in a matrix is returned either column-wise or row-wise.

Value

A vector with the column or the row products.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colsums, coldiffs, colMedians

Examples

x <- matrix( runif(100 * 10), ncol = 10 )
res<-colprods(x)
res<-rowprods(x)

x<-NULL

Column and row-wise range of values of a matrix.

Description

Column and row-wise range of values of a matrix.

Usage

colrange(x, cont = TRUE, parallel = FALSE,cores = 0)
rowrange(x, cont = TRUE)

Arguments

x

A numerical matrix or data.frame with data.

parallel

Execute algorithm in parallel for data.frame.

cont

If the data are continuous, leave this TRUE and it will return the range of values for each variable (column). If the data are integers, categorical, or if you want to find out the number of unique numbers in each column set this to FALSE.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Value

A vector with the relevant values.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colMins, colMaxs, rowMins, rowMaxs, nth, colMedians, colVars, colSort, rowSort

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )

a1 <- colrange(x) 
a2 <- apply(x, 2, function(x) diff( range(x)) ) 
all.equal(a1, a2)

a1 <- rowrange(x) 
a2 <- apply(x, 1, function(x) diff( range(x)) ) 
all.equal(a1, a2)

x<-a1<-a2<-NULL

Column and row-wise ranks

Description

Column and row-wise ranks.

Usage

colRanks(x,method = "average",descending = FALSE,
     stable = FALSE, parallel = FALSE, cores = 0)
rowRanks(x,method = "average",descending = FALSE,
     stable = FALSE, parallel = FALSE, cores = 0)
Rank(x,method = "average",descending = FALSE,stable = FALSE, parallel = FALSE)

Arguments

x

A mumerical matrix or data.frame with the data.

parallel

A boolean value for parallel version.

method

a character string for choosing method. Must be one of:

  • average : a permutation with theri mean values at each index set of ties

  • min : a permutation with minimum values at each index set of ties

  • max : a permutation with maximum values at each index set of ties

  • first : a permutation with increasing values at each index set of ties

  • random : a permutation with random values at each index set of ties

descending

A boolean value (TRUE/FALSE) for sorting the vector in descending order. By default sorts the vector in ascending.

stable

A boolean value (TRUE/FALSE) for choosing a stable sort algorithm. Stable means that discriminates on the same elements. Only for the method "first".

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

For each column or row of a matrix the ranks are calculated and they are returned.

Value

A matrix with the column or row-wise ranks.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Rank, correls

Examples

x <- matrnorm(100, 10)
a1 <- colRanks(x)
a2 <- apply(x, 2, rank)
b1 <- rowRanks(x)
b2 <- apply(x, 1, rank)

a1 <- Rank(x[,1])
a1 <- rank(x[,1])

x<-a1<-a2<-b1<-b2<-NULL

Column and row-wise Shuffle

Description

Column and row-wise shuffle of a matrix.

Usage

colShuffle(x)
rowShuffle(x)

Arguments

x

A matrix or data.frame with the data.

Details

The functions is written in C++ in order to be as fast as possible.

Value

A vector with the column/row Shuffle.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Median, colVars, colMeans (buit-in R function)

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
colShuffle(x)
rowShuffle(x)

x<-NULL

Column and row-wise sums of a matrix

Description

Column and row-wise sums of a matrix.

Usage

colsums(x,indices = NULL, parallel = FALSE, na.rm = FALSE, cores = 0)
rowsums(x,indices = NULL, parallel = FALSE, na.rm = FALSE, cores = 0)

Arguments

x

A numerical matrix with data.

indices

An integer vector with the indices to sum the columns/rows.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE. Doens't work with argument "indices".

na.rm

A logical value indicating to remove NAs. The algorithm run in parallel so do not use with option parallel.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Value

A vector with sums.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colMedians, colmeans, colVars

Examples

x <- matrix(rpois(500 * 100, 10),ncol = 100)
x1 <- colsums(x)
x2 <- colSums(x)
all.equal(x1,x2)

x1 <- rowsums(x)
x2 <- rowSums(x)
all.equal(x1,x2)

x<-x1<-x2<-NULL

Column and row-wise tabulate

Description

Column and row-wise tabulate of a matrix.

Usage

colTabulate(x, max_number = max(x))
rowTabulate(x, max_number = max(x))

Arguments

x

An integer matrix with the data. The numbers must start from 1, i.e. 1, 2, 3, 4,... No zeros are allowed. Anything else may cause a crash.

max_number

The maximum value of vector x. If you know which is the max number use this argument for faster results or by default max(x).

Details

The functions is written in C++ in order to be as fast as possible.

Value

A matrix where in each column the command "tabulate" has been performed. The number of rows of the returned matrix will be equal to the max_number if given. Otherwise, the functions will find this number.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans

Examples

x <- matrix( rbinom(100 * 100, 4, 0.5), ncol = 100 )
colTabulate(x)
rowTabulate(x)

x<-NULL

Column and row-wise variances and standard deviations of a matrix

Description

Column and row-wise variances and standard deviations of a matrix

Usage

## S3 method for class 'matrix'
colVars(x, std = FALSE, na.rm = FALSE, parallel = FALSE, cores = 0)
## S3 method for class 'data.frame'
colVars(x, std = FALSE, na.rm = FALSE, parallel = FALSE, cores = 0)
colVars(x, std = FALSE, na.rm = FALSE, parallel = FALSE, cores = 0)
rowVars(x, std = FALSE, na.rm = FALSE, parallel = FALSE, cores = 0)

Arguments

x

A matrix with the data.

std

A boolean variable specyfying whether you want the variances (FALSE) or the standard deviations (TRUE) of each column.

na.rm

TRUE or FAlSE for remove NAs if exists.

parallel

Should parallel implentations take place in C++? The default value is FALSE.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

We found this on stackoverflow which was created by David Arenburg. We then modified the function to match the sums type formula of the variance, which is faster.

Value

A vector with the column variances or standard deviations.

Author(s)

Michail Tsagris and Manos Papadakis.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colmeans, colMedians, colrange

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
a2 <- colVars(x)
x<-a2<-NULL

Column and row-wise mean absolute deviations

Description

Column and row-wise mean absolute deviations.

Usage

colMads(x,method = "median",na.rm=FALSE,parallel = FALSE, cores = 0)
rowMads(x,method = "median",na.rm=FALSE,parallel = FALSE, cores = 0)
Mad(x,method = "median",na.rm=FALSE)

Arguments

x

A vector, matrix or data.frame with the data.

method

A character vector with values "median", for median absolute deviation or "mean", for mean absolute deviation.

na.rm

A logical value TRUE/FALSE to remove NAs.

parallel

A boolean value for parallel version.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

The functions is written in C++ in order to be as fast as possible.

Value

A vector with the column-wise mean absolute deviations.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colMedians, rowMedians, colVars, colmeans, colMeans (buit-in R function)

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
a <- colMads(x)

x<-NULL

Column-wise differences

Description

Column-wise differences.

Usage

coldiffs(x)

Arguments

x

A matrix with numbers.

Details

This function simply does this function x[, -1] - x[, -k], where k is the last column of the matrix x. But it does it a lot faster. That is, 2nd column - 1st column, 3rd column - 2nd column, and so on.

Value

A matrix with one column less containing the differences between the successive columns.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Dist, dista, colmeans

Examples

x <- matrix( rnorm(50 * 10), ncol = 10 )
res<-coldiffs(x)

x<-NULL

Column-wise kurtosis and skewness coefficients

Description

Column-wise kurtosis and skewness coefficients.

Usage

colkurtosis(x, pvalue = FALSE)

colskewness(x, pvalue = FALSE)

Arguments

x

A matrix with the data, where the rows denote the samples and the columns are the variables.

pvalue

If you want a hypothesis test that the skewness or kurtosis are significant set this to TRUE. This checks whether the skewness is significantly different from 0 and whether the kurtosis is significantly different from 3.

Details

The skewness and kurtosis coefficients are calculated. For the skewness coefficient we use the sample unbiased version of the standard deviation. For the kurtosis, we do not subtract 3.

Value

If "pvalue" is FALSE, a vector with the relevant coefficient. Otherwise a matrix with two columns. The kurtosis or skewness coefficient and the p-value from the hypothesis test that they are significantly different from 3 or 0 respectively.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

skew, skew.test2, colMedians, colmeans, colVars, sftests

Examples

## 200 variables, hence 200 F-tests will be performed
x = matrix( rnorm(200 * 50), ncol = 50 )
## 200 observations in total
colkurtosis(x)
colskewness(x)
x <- NULL

Column-wise matching coefficients

Description

Column-wise matching coefficients.

Usage

match.coefs(x, y = NULL, ina, type = "jacc")

Arguments

x

A matrix with the data, where the rows denote the samples and the columns are the variables.

y

A second matrix with the data of the second group. If this is NULL (default value) then the argument ina must be supplied. Notice that when you supply the two matrices the procedure is two times faster.

ina

A numerical vector with 1s and 2s indicating the two groups. Be careful, the function is designed to accept only these two numbers. In addition, if your "y" is NULL, you must specify "ina".

type

This denotes the type of matching coefficient to calculate. For the Jaccard index put "jacc". For the simple matching coefficient put "smc" or else both of them will be calculated.

Details

Two matrices are given as imput and for each column matching coefficients are calculated, either the Jaccard or the simple matching coefficient or both.

Value

A matrix with one or two columns, depending on the type you have specified. If you specify "both", there will be two columns, if you specify "jacc" or "smc" then just one column.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

odds, colTabulate

Examples

x <- matrix(rbinom(400 * 10, 1, 0.5), ncol = 10)
y <- matrix(rbinom(400 * 10, 1, 0.5), ncol = 10)
a <- match.coefs(x, y, type = "both")
x <- NULL
y <- NULL

Column-wise minimum and maximum of a matrix

Description

Column-wise minimum and maximum of a matrix.

Usage

colMins(x, value = FALSE, parallel = FALSE, cores = 0)
colMaxs(x, value = FALSE, parallel = FALSE, cores = 0)
colMinsMaxs(x, parallel = FALSE, cores = 0)

Arguments

x

A numerical matrix or data.frame with data.

value

If the value is FALSE it returns the indices of the minimum/maximum, otherwise it returns the minimum and maximum values.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE. The parallel will return the minimum/maximum value only. It will never return the indices.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Value

A vector with the relevant values.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowMaxs, nth, colrange, colMedians, colVars, colSort, rowSort

Examples

x <- matrix( rnorm(100 * 200), ncol = 200 )

s1 <- colMins(x) 
s2 <- apply(x, 2, min) 

s1 <- colMaxs(x) 
s2 <- apply(x, 2, max) 

s1 <- colMinsMaxs(x)
s2 <- c(apply(x, 2, min), apply(x, 2, max)) 

x<-s1<-s2<-NULL

Column-wise MLE of some univariate distributions

Description

Column-wise MLE of some univariate distributions.

Usage

colexpmle(x)
colexp2.mle(x)
colgammamle(x, tol = 1e-07)
colinvgauss.mle(x)
collaplace.mle(x)
collindley.mle(x)
colmaxboltz.mle(x)
colnormal.mle(x)
colpareto.mle(x)
colrayleigh.mle(x)
colvm.mle(x, tol = 1e-07)
colweibull.mle(x, tol = 1e-09, maxiters = 100, parallel = FALSE)
colnormlog.mle(x)

Arguments

x

A numerical matrix with data. Each column refers to a different vector of observations of the same distribution. For exponential, 2 parameter exponential, Weibull, gamma, inverse Gaussian, Maxwell-Boltzman, Lindley, Rayleigh and Pareto distributions, the numbers must be greater than zero. For the Poisson and geometric distributions, the numbers must be integers, 0, 1, 2,... For the Normal and Laplace distribution the numbers can take any value. The von Mises distribution takes values beween 0 and 2 * pi (radians).

tol

The tolerance value to terminate the Newton-Fisher algorithm.

maxiters

The maximum number of iterations to implement.

parallel

Do you want to calculations to take place in parallel? The default value is FALSE

Details

For each column, the same distribution is fitted and its parameter and log-likelihood are computed.

Value

A matrix with two, three or five (for the colnormlog.mle) columns. The first one or the first two contain the parameter(s) of the distribution and the other columns contain the log-likelihood values.

Author(s)

Michail Tsagris and Stefanos Fafalios

R implementation and documentation: Michail Tsagris <[email protected]> and Stefanos Fafalios <[email protected]>

References

Kalimuthu Krishnamoorthy, Meesook Lee and Wang Xiao (2015). Likelihood ratio tests for comparing several gamma distributions. Environmetrics, 26(8):571-583.

N.L. Johnson, S. Kotz and N. Balakrishnan (1994). Continuous Univariate Distributions, Volume 1 (2nd Edition).

N.L. Johnson, S. Kotz and N. Balakrishnan (1970). Distributions in statistics: continuous univariate distributions, Volume 2.

Sharma V. K., Singh S. K., Singh U. and Agiwal V. (2015). The inverse Lindley distribution: a stress-strength reliability model with application to head and neck cancer data. Journal of Industrial and Production Engineering, 32(3): 162-173.

See Also

vm.mle, poisson.mle, normal.mle, gammamle

Examples

x <- matrix(rnorm(1000 * 50), ncol = 50)
a <- colnormal.mle(x)
b <- collaplace.mle(x)
x <- NULL

Column-wise true/false value of a matrix

Description

Column-wise true/false value of a matrix.

Usage

colTrue(x)
colFalse(x)
colTrueFalse(x)

Arguments

x

A logical matrix with data.

Value

An integer vector where item "i" is the number of the true/false values of "i" column.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowFalse, nth, colrange, colMedians, colVars, colSort, rowSort, rowTrue

Examples

x <- matrix(as.logical(rbinom(100*100,1,0.5)),100,100)

s1 <- colTrue(x) 

s1 <- colFalse(x)  

s1 <- colTrueFalse(x)

x<-s1<-NULL

Column-wise uniformity tests for circular data

Description

Column-wise uniformity tests for circular data.

Usage

colwatsons(u)

Arguments

u

A numeric matrix containing the circular data which are expressed in radians. Each column is a different sample.

Details

These tests are used to test the hypothesis that the data come from a circular uniform distribution. The Kuiper test is much more time consuming and this is why it not implemented yet. Once we figure out a way to make it fast, we will incldue it.

Value

A matrix with two columns, the value of the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Jammalamadaka, S. Rao and SenGupta, A. (2001). Topics in Circular Statistics, pg. 153-55 (Kuiper's test) & 156-157 (Watson's test).

See Also

watson, vmf.mle, rvonmises

Examples

x <- matrix( rvonmises(n = 50 * 10, m = 2, k = 0), ncol = 10 )
res<-colwatsons(x)
x <- NULL

Column-wise Yule's Y (coefficient of colligation)

Description

Column-wise Yule's Y (coefficient of colligation).

Usage

col.yule(x, y = NULL, ina)

Arguments

x

A matrix with 0 and 1. Every column refers to a different sample or variable.

y

A second matrix, of the same dimensions as x, with 0 and 1. Every column refers to a different sample or variable.

ina

If y is NULL, ina must be specified. This is a numeric vector with 1s and 2s, indicating the group of each row.

Details

Yule's coefficient of colligation is calculated for every column.

Value

A vector with Yule's Y, one for every column of x is returned.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Yule G. Udny (1912). On the Methods of Measuring Association Between Two Attributes. Journal of the Royal Statistical Society, 75(6):579-652.

See Also

yule, odds

Examples

x <- matrix(rbinom(300 * 10, 1, 0.5), ncol = 10)
ina <- rep(1:2, each = 150)
res<-col.yule( x, ina = ina )

Convert a dataframe to matrix

Description

Convert a dataframe to matrix.

Usage

data.frame.to_matrix(x,col.names = NULL,row.names = NULL)

Arguments

x

A Numeric matrix with data and NAs.

col.names

A boolean value for keeping the colnames for argument x or a character vector for the new colnames.

row.names

A boolean value for keeping the rownames for argument x or a character vector for the new rownames.

Details

This functions converts a dataframe to matrix. Even if there are factors, the function converts them into numerical values. Attributes are not allowed for now.

Value

A matrix wich has the numrical values from the dataframe.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

Match, is.symmetric, permutation

Examples

res<-data.frame.to_matrix(iris)

Convert R function to the Rfast's coresponding

Description

Convert R function to the Rfast's coresponding.

Usage

as.Rfast.function(Rfunction.name,margin=NULL)

Arguments

Rfunction.name

An character value with the name of the function.

margin

A logical function for return the column-row wise function.

Details

Given the name of R function, it returns the coresponding function's name from Rfast.

Value

The coresponding Rfast function.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

See Also

colsums, colMedians, colVars

Examples

res<-as.Rfast.function("var")

Correlation based forward regression.

Description

Correlation based forward regression.

Usage

cor.fsreg(y, x, ystand = TRUE, xstand = TRUE, threshold = 0.05, 
tolb = 2, tolr = 0.02, stopping = "BIC")

Arguments

y

A numerical vector.

x

A matrix with data, the predictor variables.

ystand

If this is TRUE the response variable is centered. The mean is subtracted from every value.

xstand

If this is TRUE the independent variables are standardised.

threshold

The significance level, set to 0.05 by default. Bear in mind that the logarithm of it is used, as the logarithm of the p-values is calculated at every point. This will avoid numerical overflows and small p-values, less than the machine epsilon, being returned as zero.

tolb

If we see only the significane of the variables, many may enter the linear regression model. For this reason, we also use the BIC as a way to validate the inclusion of a candidate variable. If the BIC difference between two successive models is less than the tolerance value, the variable will not enter the model, even if it statistically significant. Set it to 0 if you do not want this extra check.

tolr

This is an alternative to the BIC change and it uses the adjusted coefficient of determination. If the increase in the adjusted R2R^2 is more than the tolr continue.

stopping

This refers to the type of extra checking to do. If you want the BIC check, set it to "BIC". If you want the adjusted R2R^2 check set this to "ar2". Or, if you want both of them to take place, both of these criteria to be satisfied make this "BICR2".

Details

The forward regression tries one by one the variables using the F-test, basically partial F-test every time for the latest variable. This is the same as testing the significance of the coefficient of this latest enetered variable. Alternatively the correlation can be used and this case the partial correlation coefficient. There is a direct relationship between the t-test statistic and the partial correlation coefficient. Now, instead of having to calculate the test statistic, we calculate the partial correlation coefficient. Using Fisher's z-transform we get the variance imediately. The partial correlation coefficient, using Fisher's z-transform, and the partial F-test (or the coefficient's t-test statistic) are not identical. They will be identical for large sample sizes though.

Value

A matrix with three columns, the index of the selected variables, the logged p-value and the the test statistic value and the BIC or adjusted R2R^2 of each model. In the case of stopping="BICR2" both of these criteria will be returned.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

See Also

score.glms, univglms, logistic_only, poisson_only, regression

Examples

## 200 variables, hence 200 univariate regressions are to be fitted
x <- matrnorm(200,  100)
y <- rnorm(200)
cor.fsreg(y, x)
x <- NULL

Correlation between pairs of variables

Description

Correlations between pairs of variables.

Usage

corpairs(x, y, rho = NULL, logged = FALSE, parallel = FALSE)

Arguments

x

A matrix with real valued data.

y

A matrix with real valued data whose dimensions match those of x.

rho

This can be a vector of assumed correlations (equal to the number of variables or the columns of x or y) to be tested. If this is not the case, leave it NULL and only the correlations will be returned.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)? This is taken into account only if "rho" is a vector.

parallel

Should parallel implentations take place in C++? The default value is FALSE.

Details

The paired correlations are calculated. For each column of the matrices x and y the correlation between them is calculated.

Value

A vector of correlations in the case of "rho" being NULL, or a matrix with two extra columns, the test statistic and the (logged) p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Lambert Diane (1992). Zero-Inflated Poisson Regression, with an Application to Defects in Manufacturing. Technometrics. 34(1):1-14.

Johnson Norman L., Kotz Samuel and Kemp Adrienne W. (1992). Univariate Discrete Distributions (2nd ed.). Wiley

Cohen, A. Clifford (1960). Estimating parameters in a conditional Poisson distribution. Biometrics. 16:203-211.

Johnson, Norman L. Kemp, Adrianne W. Kotz, Samuel (2005). Univariate Discrete Distributions (third edition). Hoboken, NJ: Wiley-Interscience.

See Also

correls, allbetas, mvbetas

Examples

x <- matrnorm(100, 100)
y <- matrnorm(100, 100)
corpairs(x, y)
a <- corpairs(x, y)
x <- NULL
y <- NULL

Correlation between a vector and a set of variables

Description

Correlation between a vector and a set of variables.

Usage

correls(y, x, type = "pearson", a = 0.05, rho = 0)
groupcorrels(y, x, type = "pearson", ina)

Arguments

y

A numerical vector.

x

A matrix with the data.

type

The type of correlation you want. "pearson" and "spearman" are the two supported types for the "correls" because their standard error is easily calculated. For the "groupcorrels" you can also put "kendall" because no hypothesis test is performed in that function.

a

The significance level used for the confidence intervals.

rho

The value of the hypothesised correlation to be used in the hypothesis testing.

ina

A factor variable or a numeric variable idicating the group of each observation.

Details

The functions uses the built-in function "cor" which is very fast and then includes confidence intervals and produces a p-value for the hypothesis test.

Value

For the "correls" a matrix with 5 column; the correlation, the p-value for the hypothesis test that each of them is eaqual to "rho", the test statistic and the $a/2%$ lower and upper confidence limits.

For the "groupcorrels" a matrix with rows equal to the number of groups and columns equal to the number of columns of x. The matrix contains the correlations only, no statistical hypothesis test is performed.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

allbetas, univglms

Examples

x <- matrnorm(60, 100 )
y <- rnorm(60)
r <- cor(y, x)  ## correlation of y with each of the xs
a <- allbetas(y, x)  ## the coefficients of each simple linear regression of y with x
b <- correls(y, x)
ina <- rep(1:2, each = 30)
b2 <- groupcorrels(y, x, ina = ina) 
x <- NULL

Fast covariance and correlation matrix calculation

Description

Fast covariance and correlation matrix calculation.

Usage

cova(x, center = FALSE, large = FALSE)

cora(x, large = FALSE)

Arguments

x

A matrix with data. It has to be matrix, if it is data.frame for example the function does not turn it into a matrix.

center

If you want to center the data prior to applying the cross product of the mateix set this equal to TRUE, otherwise leave it NULL.

large

If you have large matrices, with thousands of rows and or many tens or hundreds of columns set this equal to TRUE in order to use Rfast's Crossprod or Tcrossprod functions. These functions are twice or up to 3 times faster than the correpsonding built-in functions.

Details

The calculations take place faster than the built-in functions cor as the number of variables increases. This is true if the number of variables is high, say from 500 and above. The "cova" on the other hand is always faster. For the "cova" in specific, we have an option to center the data prior to the cross product. This can be more stable if you have many tens of thousands of rows due to numerical issues that can arise.

For the correlation matrix we took the code from here

https://stackoverflow.com/questions/18964837/fast-correlation-in-r-using-c-and-parallelization/18965892#18965892

Value

The covariance or the correlation matrix.

Author(s)

Michail Tsagris and Manos Papadakis <[email protected]>.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colVars, cor, cov

Examples

x <- matrnorm(100, 40)
s1 <- cov(x) 
s2 <- cova(x)
all.equal(s1, s2)
x <- NULL

Cox confidence interval for the ratio of two Poisson variables

Description

Cox confidence interval for the ratio of two Poisson variables.

Usage

cox.poisrat(x, y, alpha = 0.05)
col.coxpoisrat(x, y, alpha = 0.05)

Arguments

x

A numeric vector or a matrix with count data.

y

A numeric vector or a matrix with count data.

alpha

The 1 - confidence level. The default value is 0.05.

Details

Cox confidence interval for the ratio of two Poisson means is calculated.

Value

For the cox.poisrat a vector with three elements, the ratio and the lower and upper confidence interval limits. For the col.coxpoisrat a matrix with three columns, the ratio and the lower and upper confidence interval limits.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Krishnamoorthy K., Peng J. and Zhang D. (2016). Modified large sample confidence intervals for Poisson distributions: Ratio, weighted average, and product of means. Communications in Statistics-Theory and Methods, 45(1): 83-97.

See Also

correls, Table

Examples

x <- rpois(100, 10)
y <- rpois(100, 10)
res<-cox.poisrat(x, y)

Cross-Validation for the k-NN algorithm

Description

Cross-Validation for the k-NN algorithm.

Usage

knn.cv(folds = NULL, nfolds = 10, stratified = FALSE, seed = NULL, y, x, k, 
dist.type = "euclidean", type = "C", method = "average", freq.option = 0, 
pred.ret = FALSE, mem.eff = FALSE)

Arguments

folds

A list with the indices of the folds.

nfolds

The number of folds to be used. This is taken into consideration only if "folds" is NULL.

stratified

Do you want the folds to be selected using stratified random sampling? This preserves the analogy of the samples of each group. Make this TRUE if you wish, but only for the classification. If you have regression (type = "R"), do not put this to TRUE as it will cause problems or return wrong results.

seed

If NULL different folds will be created every time. Otherwise set your own seed.

y

A vector of data. The response variable, which can be either continuous or categorical (factor is acceptable).

x

A matrix with the available data, the predictor variables.

k

A vector with the possible numbers of nearest neighbours to be considered.

dist.type

The type of distance to be used, "euclidean" or "manhattan".

type

Do you want to do classification ("C") or regression ("R")?

method

If you do regression (type = "R"), then how should the predicted values be calculated? Choose among the average ("average"), median ("median") or the harmonic mean ("harmonic") of the closest neighbours.

freq.option

If classification (type = "C") and ties occur in the prediction, more than one class have the same number of k nearest neighbours, there are three strategies available. Option 0 selects the first most frequent encountered. Option 1 randomly selects the most frequent value, in the case that there are duplicates.

pred.ret

If you want the predicted values returned set this to TRUE.

mem.eff

Boolean value indicating a conservative or not use of memory. Lower usage of memory/Having this option on will lead to a slight decrease in execution speed and should ideally be on when the amount of memory in demand might be a concern.

Details

The concept behind k-NN is simple. Suppose we have a matrix with predictor variables and a vector with the response variable (numerical or categorical). When a new vector with observations (predictor variables) is available, its corresponding response value, numerical or categorical, is to be predicted. Instead of using a model, parametric or not, one can use this ad hoc algorithm.

The k smallest distances between the new predictor variables and the existing ones are calculated. In the case of regression, the average, median, or harmonic mean of the corresponding response values of these closest predictor values are calculated. In the case of classification, i.e. categorical response value, a voting rule is applied. The most frequent group (response value) is where the new observation is to be allocated.

This function does the cross-validation procedure to select the optimal k, the optimal number of nearest neighbours. The optimal in terms of some accuracy metric. For the classification it is the percentage of correct classification and for the regression the mean squared error.

Value

A list including:

preds

If pred.ret is TRUE the predicted values for each fold are returned as elements in a list.

crit

A vector whose length is equal to the number of k and is the accuracy metric for each k.

Author(s)

Marios Dimitriadis

R implementation and documentation: Marios Dimitriadis <[email protected]>

References

Friedman J., Hastie T. and Tibshirani R. (2017). The elements of statistical learning. New York: Springer.

Cover TM and Hart PE (1967). Nearest neighbor pattern classification. IEEE Transactions on Information Theory. 13(1):21-27.

Tsagris Michail, Simon Preston and Andrew T.A. Wood (2016). Improved classification for compositional data using the α\alpha-transformation. Journal of classification 33(2): 243-261.

See Also

knn, Dist, dista, dirknn.cv

Examples

x <- as.matrix(iris[, 1:4])
y <- iris[, 5]
mod <- knn.cv(folds = NULL, nfolds = 10, stratified = FALSE, seed = NULL, y = y, x = x, 
k = c(3, 4), dist.type = "euclidean", type = "C", method = "average", 
freq.option = 0, pred.ret = FALSE, mem.eff = FALSE)

Cross-Validation for the k-NN algorithm using the arc cosinus distance

Description

Cross-Validation for the k-NN algorithm using the arc cosinus distance.

Usage

dirknn.cv(y, x, k = 5:10, type = "C", folds = NULL, nfolds = 10,
stratified = TRUE, seed = NULL, parallel = FALSE, pred.ret = FALSE)

Arguments

y

A vector of data. The response variable, which can be either continuous or categorical (factor is acceptable).

x

A matrix with the available data, the predictor variables.

k

A vector with the possible numbers of nearest neighbours to be considered.

type

If your response variable y is numerical data, then this should be "R" (regression) or "WR" for distance weighted based nearest neighbours. If y is in general categorical set this argument to "C" (classification) or to "WC" for distance weighted based nearest neighbours.

folds

A list with the indices of the folds.

nfolds

The number of folds to be used. This is taken into consideration only if "folds" is NULL.

stratified

Do you want the folds to be selected using stratified random sampling? This preserves the analogy of the samples of each group. Make this TRUE if you wish, but only for the classification. If you have regression (type = "R"), do not put this to TRUE as it will cause problems or return wrong results.

seed

If NULL different folds will be created every time. Otherwise set your own seed.

parallel

Do you want th ecalculations to take place in parallel? The default value is FALSE.

pred.ret

If you want the predicted values returned set this to TRUE.

Details

The concept behind k-NN is simple. Suppose we have a matrix with predictor variables and a vector with the response variable (numerical or categorical). When a new vector with observations (predictor variables) is available, its corresponding response value, numerical or categorical, is to be predicted. Instead of using a model, parametric or not, one can use this ad hoc algorithm.

The k smallest distances between the new predictor variables and the existing ones are calculated. In the case of regression, the average, median, or harmonic mean of the corresponding response values of these closest predictor values are calculated. In the case of classification, i.e. categorical response value, a voting rule is applied. The most frequent group (response value) is where the new observation is to be allocated.

This function does the cross-validation procedure to select the optimal k, the optimal number of nearest neighbours. The optimal in terms of some accuracy metric. For the classification it is the percentage of correct classification and for the regression the mean squared error.

Value

A list including:

preds

If pred.ret is TRUE the predicted values for each fold are returned as elements in a list.

crit

A vector whose length is equal to the number of k and is the accuracy metric for each k. For the classification case it is the percentage of correct classification. For the regression case the mean square of prediction error.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris [email protected].

References

Friedman J., Hastie T. and Tibshirani R. (2017). The elements of statistical learning. New York: Springer.

Cover TM and Hart PE (1967). Nearest neighbor pattern classification. IEEE Transactions on Information Theory. 13(1):21-27.

See Also

dirknn, knn.cv, knn

Examples

x <- as.matrix(iris[, 1:4])
x <- x / sqrt( Rfast::rowsums(x^2) )
y <- iris[, 5]
mod <- dirknn.cv(y = y, x = x, k = c(3, 4) )

Density of the multivariate normal and t distributions

Description

Density of the multivariate normal and t distributions.

Usage

dmvnorm(x, mu, sigma, logged = FALSE) 
dmvt(x, mu, sigma, nu, logged = FALSE)

Arguments

x

A numerical matrix with the data. The rows correspond to observations and the columns to variables.

mu

The mean vector.

sigma

The covariance matrix.

nu

The degrees of freedom for the multivariate t distribution.

logged

Should the logarithm of the density be returned (TRUE) or not (FALSE)?

Details

The (log) density of the multivariate normal distribution is calculated for given mean vector and covariance matrix.

Value

A numerical vector with the density values calculated at each vector (row of the matrix x).

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Kanti V. Mardia, John T. Kent and John M. Bibby (1979). Multivariate analysis. Academic Press, London.

See Also

rmvnorm, rmvt, mvnorm.mle, iag.mle

Examples

x <- matrnorm(100, 20)
mu <- colmeans(x)
s <- cova(x)
a1 <- dmvnorm(x, mu, s) 
a2 <- dmvt(x, mu, s, 1)
x <- NULL

Diagonal Matrix

Description

Fill the diagonal of a matrix or create a diagonal and initialize it with a specific value.

Usage

Diag.fill(x,v=0)
Diag.matrix(len,v=0)

Arguments

x

A matrix with data.

len

Number of columns or rows.

v

Value or vector to initialize the diagonal of a matrix.By default "v=0".

Value

Diag.fill returns a diagonal matrix where all the elements in the diagonal are equal to "v".

Diag.matrix returns a diagonal matrix where has dimension "len,len" and all the elements in the diagonal are equal to "v". It is fast for huge matrices with dimensions more than [row,col] = [500,500]

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, colFalse, nth, rowrange, rowMedians, rowVars, colSort, rowSort, colTrue

Examples

x <- matrix(rbinom(100*100,1,0.5),100,100)

f <- Diag.fill(x,1)
f <- Diag.fill(x,1:100) ##equals to diag(x)<-1:100
f <- Diag.matrix(100,1) ##equals to diag(1,100,100)
f <- Diag.matrix(100,1:100) ##equals to diag(1:100,100,100)

f<-x<-NULL

Distance between vectors and a matrix - Sum of all pairwise distances in a distance matrix.

Description

Distance between vectors and a matrix - Sum of all pairwise distances in a distance matrix..

Usage

dista(xnew, x, type = "euclidean", k = 0, index = FALSE, 
 trans = TRUE, square = FALSE, p = 0, parallel = FALSE)
total.dista(xnew, x, type = "euclidean", k = 0,
 square = FALSE, p = 0, parallel = FALSE)

Arguments

xnew

A matrix with some data or a vector.

x

A matrix with the data, where rows denotes observations (vectors) and the columns contain the variables.

type

This can be either "euclidean" or "manhattan".

k

Should the k smaller distances or their indices be returned? If k > 0 this will happen.

index

In case k is greater than 0, you have the option to get the indices of the k smallest distances.

trans

Do you want the returned matrix to be transposed? TRUE or FALSE.

square

If you choose "euclidean" or "hellinger" as the method, then you can have the option to return the squared Euclidean distances by setting this argument to TRUE.

p

This is for the the Minkowski, the power of the metric.

parallel

For methods kullback_leibler, jensen_shannon and itakura_saito, you can run the algorithm in parallel.

Details

The target of this function is to calculate the distances between xnew and x without having to calculate the whole distance matrix of xnew and x. The latter does extra calculations, which can be avoided.

  • euclidean : (PiQi2)\sum \sqrt( \sum | P_i - Q_i |^2)

  • manhattan : PiQi\sum \sum | P_i - Q_i |

  • minimum : minPiQi\sum \min | P_i - Q_i |

  • maximum : maxPiQi\sum \max | P_i - Q_i |

  • minkowski : (PiQip)(1/p)\sum ( \sum | P_i - Q_i |^p)^(1/p)

  • bhattacharyya : ln(PiQi)\sum - ln \sum \sqrt(P_i * Q_i)

  • hellinger : 2(1(PiQi))\sum 2 * \sqrt( 1 - \sum \sqrt(P_i * Q_i))

  • kullback_leibler : Pilog(Pi/Qi)\sum \sum P_i * log(P_i / Q_i)

  • jensen_shannon : 0.5(Pilog(2Pi/Pi+Qi)+Qilog(2Qi/Pi+Qi))\sum 0.5 * ( \sum P_i * log(2 * P_i / P_i + Q_i) + \sum Q_i * log(2 * Q_i / P_i + Q_i))

  • canberra : PiQi/(Pi+Qi)\sum \sum | P_i - Q_i | / (P_i + Q_i)

  • chi_square XX^2 : ((PiQi)2/(Pi+Qi))\sum \sum ( (P_i - Q_i )^2 / (P_i + Q_i) )

  • soergel : PiQi/max(Pi,Qi)\sum \sum | P_i - Q_i | / \sum \max(P_i , Q_i)

  • sorensen : PiQi/(Pi+Qi)\sum \sum | P_i - Q_i | / \sum (P_i + Q_i)

  • cosine : (PiQi)/(Pi2)(Qi2)\sum (P_i * Q_i) / \sqrt(\sum P_i^2) * \sqrt(\sum Q_i^2)

  • wave_hedges : PiQi/max(Pi,Qi)\sum \sum | P_i - Q_i | / \max(P_i , Q_i)

  • motyka : min(Pi,Qi)/(Pi+Qi)\sum \sum \min(P_i , Q_i) / (P_i + Q_i)

  • harmonic_mean : 2(PiQi)/(Pi+Qi)2 * \sum (P_i * Q_i) / (P_i + Q_i)

  • jeffries_matusita : (22(PiQi))\sum \sqrt( 2 - 2 * \sum \sqrt(P_i * Q_i))

  • gower : 1/dPiQi\sum 1/d * \sum | P_i - Q_i |

  • kulczynski : 1/PiQi/min(Pi,Qi)\sum 1 / \sum | P_i - Q_i | / \sum \min(P_i , Q_i)

Value

A matrix with the distances of each xnew from each vector of x. The number of rows of the xnew and and the number of columns of xnew are the dimensions of this matrix.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

mahala, Dist, total.dist, total.dista

Examples

xnew <- as.matrix( iris[1:10, 1:4] )
x <- as.matrix( iris[-c(1:10), 1:4] )
a <- dista(xnew, x)
b <- as.matrix( dist( rbind(xnew, x) ) )
b <- b[ 1:10, -c(1:10) ]
sum( abs(a - b) )

## see the time
x <- matrix( rnorm(1000 * 4), ncol = 4 )
dista(xnew, x)
as.matrix( dist( rbind(xnew, x) ) )

x<-b<-a<-xnew<-NULL

Distance correlation

Description

Distance correlation.

Usage

dcor(x, y)
bcdcor(x, y)

Arguments

x

A numerical matrix.

y

A numerical matrix.

Details

The distance correlation or the bias corrected distance correlation of two matrices is calculated. The latter one is used for the hypothesis test that the distance correlation is zero (see dcor.ttest).

Value

For the bias corrected distance correlation its value only. For the distance correlation a list including:

dcov

The distance covariance.

dvarX

The distance variance of x.

dvarY

The distance variance of Y.

dcor

The distance correlation.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

G.J. Szekely, M.L. Rizzo and N. K. Bakirov (2007). Measuring and Testing Independence by Correlation of Distances. Annals of Statistics, 35(6):2769-2794.

See Also

dcov, dcor.ttest, edist

Examples

x <- as.matrix(iris[1:50, 1:4])
y <- as.matrix(iris[51:100, 1:4])
res<-dcor(x, y)
res<-bcdcor(x, y)

x<-y<-NULL

Distance matrix - Sum of all pairwise distances in a distance matrix

Description

Distance matrix - Sum of all pairwise distances in a distance matrix.

Usage

Dist(x, method = "euclidean", square = FALSE, p = 0,vector = FALSE)
total.dist(x, method = "euclidean", square = FALSE, p = 0)
vecdist(x)

Arguments

x

A matrix with data. The distances will be calculated between pairs of rows. In the case of vecdist this is a vector. For the haversine distance it must be a matrix with two columns, the first column is the latitude and the second the longitude (in radians).

method

See details for the available methods.

square

If you choose "euclidean" or "hellinger" as the method, then you can have the option to return the squared Euclidean distances by setting this argument to TRUE.

p

This is for the the Minkowski, the power of the metric.

vector

For return a vector instead a matrix.

Details

The distance matrix is compute with an extra argument for the Euclidean distances. The "kullback_leibler" refers to the symmetric Kullback-Leibler divergence.

  • euclidean : (PiQi2)\sqrt( \sum | P_i - Q_i |^2)

  • manhattan : PiQi\sum | P_i - Q_i |

  • minimum : minPiQi\min | P_i - Q_i |

  • maximum : maxPiQi\max | P_i - Q_i |

  • minkowski : (PiQip)(1/p)( \sum | P_i - Q_i |^p)^(1/p)

  • bhattacharyya : ln(PiQi)- ln \sum \sqrt(P_i * Q_i)

  • hellinger : 2(1(PiQi))2 * \sqrt( 1 - \sum \sqrt(P_i * Q_i))

  • kullback_leibler : Pilog(Pi/Qi)\sum P_i * log(P_i / Q_i)

  • jensen_shannon : 0.5(Pilog(2Pi/Pi+Qi)+Qilog(2Qi/Pi+Qi))0.5 * ( \sum P_i * log(2 * P_i / P_i + Q_i) + \sum Q_i * log(2 * Q_i / P_i + Q_i))

  • haversine : 2Rarcsin((sin((lat2lat1)/2)2+cos(lat1)cos(lat2)sin((lon2lon1)/2)2))2 * R * \arcsin(\sqrt(\sin((lat_2 - lat_1)/2)^2 + \cos(lat_1) * \cos(lat_2) * \sin((lon_2 - lon_1)/2)^2))

  • canberra : PiQi/(Pi+Qi)\sum | P_i - Q_i | / (P_i + Q_i)

  • chi_square XX^2 : ((PiQi)2/(Pi+Qi))\sum ( (P_i - Q_i )^2 / (P_i + Q_i) )

  • soergel : PiQi/max(Pi,Qi)\sum | P_i - Q_i | / \sum \max(P_i , Q_i)

  • sorensen : PiQi/(Pi+Qi)\sum | P_i - Q_i | / \sum (P_i + Q_i)

  • cosine : (PiQi)/(Pi2)(Qi2)\sum (P_i * Q_i) / \sqrt(\sum P_i^2) * \sqrt(\sum Q_i^2)

  • wave_hedges : PiQi/max(Pi,Qi)\sum | P_i - Q_i | / \max(P_i , Q_i)

  • motyka : min(Pi,Qi)/(Pi+Qi)\sum \min(P_i , Q_i) / (P_i + Q_i)

  • harmonic_mean : 2(PiQi)/(Pi+Qi)2 * \sum (P_i * Q_i) / (P_i + Q_i)

  • jeffries_matusita : (22(PiQi))\sqrt( 2 - 2 * \sum \sqrt(P_i * Q_i))

  • gower : 1/dPiQi1/d * \sum | P_i - Q_i |

  • kulczynski : 1/PiQi/min(Pi,Qi)1 / \sum | P_i - Q_i | / \sum \min(P_i , Q_i)

Value

A square matrix with the pairwise distances.

Author(s)

Manos Papadakis.

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Mardia K. V., Kent J. T. and Bibby J. M. (1979). Multivariate Analysis. Academic Press.

See Also

dista, colMedians

Examples

x <- matrix(rnorm(50 * 10), ncol = 10)
a1 <- Dist(x)
a2 <- as.matrix( dist(x) )

x<-a1<-a2<-NULL

Distance variance and covariance

Description

Distance variance and covariances.

Usage

dvar(x)
dcov(x, y)

Arguments

x

A numerical matrix or a vector.

y

A numerical matrix or a vector.

Details

The distance variance of a matrix/vector or the distance covariance of two matrices is calculated. For the distance variance of a vector we use the fast method of Huo and Szekely (2016).

Value

The distance covariance or distance variance.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Szekely G.J., Rizzo M.L. and Bakirov N.K.(2007). Measuring and Testing Independence by Correlation of Distances. Annals of Statistics, 35(6):2769-2794.

Huo X. and Szekely G. J. (2016). Fast computing for distance covariance. Technometrics, 58(4): 435-447.

See Also

dcor, edist

Examples

x <- as.matrix(iris[1:50, 1:4])
y <- as.matrix(iris[51:100, 1:4])
res <- dcov(x, y)
res <- dvar(x[, 1])

Eigenvalues in high dimensional principal component analysis

Description

Eigenvalues in high dimensional (n<<p) principal component analysis.

Usage

hd.eigen(x, center = TRUE, scale = FALSE, k = NULL, vectors = FALSE, large = FALSE)

Arguments

x

A numerical n×pn \times p matrix with data where the rows are the observations and the columns are the variables.

center

Do you want your data centered? TRUE or FALSE.

scale

Do you want each of your variables scaled, i.e. to have unit variance? TRUE or FALSE.

k

If you want a specific number of eigenvalues and eigenvectors set it here, otherwise all eigenvalues (and eigenvectors if requested) will be returned.

vectors

Do you want the eigenvectors be returned? By dafault this is FALSE.

large

If you have large matrices, with thousands of rows and or many tens or hundreds of columns set this equal to TRUE in order to use Rfast's Crossprod or Tcrossprod functions. These functions are twice or up to 3 times faster than the correpsonding built-in functions.

Details

When n<<pn<<p, at most the first n eigenvalues are non zero. Hence, there is no need to calculate the other p-n zero eigenvalues. When center is TRUE, the eigenvalues of the covariance matrix are calculated. When both the center and scale is TRUE the eigenvalues of the correlation matrix are calculated. One or more eigenvectors (towards the end) will be 0. In general the signs might be the opposite than R's, but this makes no difference. We use the Crossprod instead of the relevant built-in function. The higher the dimensions of the matrix are the faster this function becomes.

Value

A list including:

values

A vector with the n (or first k) eigenvalues. The divisor in the crossproduc matrix is n-1 and not n.

vectors

A matrix of p×np \times n or p×kp \times k eigenvectors.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris <[email protected]>.

See Also

rmdp

Examples

x <- matrnorm( 40, 100)
a <- hd.eigen(x, FALSE, FALSE)
b <- prcomp(x, center = FALSE, scale = FALSE)
a
b$sdev^2
x <- NULL

Empirical and exponential empirical likelihood tests for one sample

Description

Empirical and exponential empirical likelihood tests for one sample.

Usage

eel.test1(x, mu, tol = 1e-09, logged = FALSE)
el.test1(x, mu, tol = 1e-07, logged = FALSE)

Arguments

x

A numerical vector.

mu

The hypothesised mean value.

tol

The tolerance value to stop the iterations of the Newton-Raphson.

logged

Should the logarithm of the p-value be returned? TRUE or FALSE.

Details

Exponential empirical likelihood is a non parametric method. In this case we use it as the non parametric alternative to the t-test. Newton-Raphson is used to maximise the log-likelihood ratio test statistic. In the case of no solution, NULL is returned. Despite the function having beeen written in R, it is pretty fast. As for the empirical likelihood ratio test, there is a condition for the range of possible values of mu. If mu is outside this range it is rejected immediately.

Value

iters

The number of iterations required by the Newton-Raphson algorithm. If no covnergence occured this is NULL. This is not returned for the empircial likelihood ratio test.

info

A vector with three elements, the value of the λ\lambda, the likelihood ratio test statistic and the relevant p-value. If no convergence occured, the value of the λ\lambda before is becomes NA, the value of test statistic is 10510^5 and the p-value is 0. No convergence can be interpreted as rejection of the hypothesis test.

p

The estimated probabilities, one for each observation. If no covnergence occured this is NULL.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Owen A. B. (2001). Empirical likelihood. Chapman and Hall/CRC Press.

See Also

ftest, ttest1

Examples

x <- rnorm(500)
a1 <- eel.test1(x, 0)
a2 <- el.test1(x, 0)

Empirical and exponential empirical likelihood tests for two samples

Description

Empirical and exponential empirical likelihood tests for two samples.

Usage

eel.test2(x, y, tol = 1e-09, logged = FALSE)
el.test2(x, y, tol = 1e-07, logged = FALSE)

Arguments

x

A numerical vector.

y

Another numerical vector.

tol

The tolerance value to stop the iterations of the Newton-Raphson.

logged

Should the logarithm of the p-value be returned? TRUE or FALSE.

Details

Empirical and exponential empirical likelihood are two non parametric hypothesis testing methods. We can use them as non parametric alternatives to the t-test. Newton-Raphson is used to maximise the log-likelihood ratio test statistic. In the case of no solution, NULL is returned.

Value

iters

The number of iterations required by the Newton-Raphson algorithm. If no covnergence occured this is NULL.

info

A vector with three elements, the value of the λ\lambda, the likelihood ratio test statistic and the relevant p-value. If no convergence occured, the value of the λ\lambda before is becomes NA, the value of test statistic is 10510^5 and the p-value is 0. No convergence can be interpreted as rejection of the hypothesis test.

p1

The estimated probabilities, one for each observation for the first sample. If no covnergence occured this is NULL.

p2

The estimated probabilities, one for each observation for the second sample. If no covnergence occured this is NULL.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Owen A. B. (2001). Empirical likelihood. Chapman and Hall/CRC Press.

See Also

ftests, ttests, ttest

Examples

x <- rnorm(200)
y <- rnorm(300)
eel.test2(x, y)
el.test2(x, y)

Energy distance between matrices

Description

Energy distance between matrices.

Usage

edist(x, y=NULL)

Arguments

x

A matrix with numbers or a list with matrices.

y

A second matrix with data. The number of columns of x and y must match. The number of rows can be different.

Details

This calculates the energy distance between two matrices. It will work even for tens of thousands of rows, it will just take some time. See the references for more information. If you have many matrices and want to calculate the distance matrix, then put them in a list and use the function.

Value

If "x" is matrix, a numerical value, the energy distance. If "x" is list, a matrix with all pairwsie distances of the matrices.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Szekely G. J. and Rizzo M. L. (2004) Testing for Equal Distributions in High Dimension, InterStat, November (5).

Szekely G. J. (2000) Technical Report 03-05, E-statistics: Energy of Statistical Samples, Department of Mathematics and Statistics, Bowling Green State University.

Sejdinovic D., Sriperumbudur B., Gretton A. and Fukumizu, K. (2013). Equivalence of distance-based and RKHS-based statistics in hypothesis testing. The Annals of Statistics, 41(5), 2263-2291.

See Also

dvar, total.dist, total.dista, Dist, dista

Examples

x <- as.matrix( iris[1:50, 1:4] )
y <- as.matrix( iris[51:100, 1:4] )
res<-edist(x, y)
z <- as.matrix(iris[101:150, 1:4])
a <- list()
a[[ 1 ]] <- x
a[[ 2 ]] <- y
a[[ 3 ]] <- z
res<-edist(a)

x<-y<-z<-a<-NULL

Equality of objects

Description

Equality of objects.

Usage

all_equals(x,y,round_digits = FALSE,without_attr=FALSE,fast_result=FALSE)

Arguments

x

A Matrix, List, Dataframe or Vector.

y

A Matrix, List, Dataframe or Vector.

round_digits

The digit for rounding numbers.

without_attr

A boolean value (TRUE/FALSE) for deleting attributes. Be carefull although because some atributes are very important for you item.

fast_result

A boolean value (TRUE/FALSE) for using just identical.But you can combine only with round_digits argument.

Value

A boolean (TRUE/FALSE) value which represents if the items x and y are equal.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Match, mvbetas, correls, univglms, colsums, colVars

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
y <- matrix( rnorm(100 * 100), ncol = 100 )
all_equals(x,y) 
all_equals(x, x)

Estimation of an AR(1) model

Description

Estimation of an AR(1) model.

Usage

ar1(y, method = "cmle") 
colar1(y, method = "cmle")

Arguments

y

For the case of ar1 this is a vector of time series. For the case of colar1 this is a matrix where weach column represents a time series.

method

This can be either "cmle" for conditional maximum likelihood or "yw" for the Yule-Walker equations.

Details

Instead of the classical MLE for the AR(1) model which requires numerical optimsation (Newton-Raphson for example) we estimate the parameters of the AR(1) model using conditional maximum likelihood. This procedure is described in Chapter 17 in Lee (2006). In some, it assumes that the first observation is deterministic and hence conditioning on that observation, there is a closed form solution for the parameters. The second alternative is to use the method of moments and hence the Yule-Walker equations.

Value

param

For the case of ar1 this is a vector with three elements, the constant term, the ϕ\phi term (lag coefficient) and the variance. For the case of colar1 this is a matrix with three columns, eahc of which carries the same aforementioned elements.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

http://econ.nsysu.edu.tw/ezfiles/124/1124/img/Chapter17_MaximumLikelihoodEstimation.pdf

See Also

rm.lines, varcomps.mle, rm.anovas

Examples

y <- as.vector(lh)
ar1(y)
ar(y, FALSE, 1, "ols")

ar1(y, method = "yw")
ar(y, FALSE, 1, "yw")

a1 <- colar1(cbind(y, y) )
b1 <- colar1(cbind(y, y), method = "yw")

Estimation of the Box-Cox transformation

Description

Estimation of the Box-Cox transformation.

Usage

bc(x, low = -1, up = 1)

Arguments

x

A numerical vector with strictly positive values.

low

The lowest value to search for the best λ\lambda parameter.

up

The highest value to search for the best λ\lambda parameter.

Details

The functions estimates the best λ\lambda in the Box-Cox power transformation.

Value

The optimal value of λ\lambda.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Box George E. P. and Cox D. R. (1964). An analysis of transformations. Journal of the Royal Statistical Society, Series B, 26 (2):211-252.

See Also

correls, auc

Examples

x <- exp(rnorm(1000))
res<-bc(x)

Exact t-test for 2 independent samples

Description

Exact t-test for 2 independent samples.

Usage

exact.ttest2(x, y)

Arguments

x

A numerical vector with the data.

y

A numerical vector with the data.

Details

This function performs an exact t-test. With few observations, permutation or bootstrap calculation of the p-value is advisable. However, with even fewer observations, one can perform all possible permutations and calculate the exact p-value. This is what this function does. BUT, pay attention, as this works with few samples. If for example each sample contains 15 numbers, you will need a lot of memory (more than 17 GB) for this function to work. the reason is that we create the matrix with all possible permutations first and then perform the two-sample t-test.

Value

A vector with the number of permutations, test statistic and the permutation based p-value.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

B.L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

See Also

boot.ttest2, ttest2, ftest

Examples

x <- rnorm(7)
y <- rnorm(7)
res<-exact.ttest2(x, y)

Exponential empirical likelihood for a one sample mean vector hypothesis testing

Description

Exponential empirical likelihood for a one sample mean vector hypothesis testing.

Usage

mv.eeltest1(x, mu, tol = 1e-06)

Arguments

x

A matrix containing Euclidean data.

mu

The hypothesized mean vector.

tol

The tolerance value used to stop the Newton-Raphson algorithm.

Details

Multivariate hypothesis test for a one sample mean vector. This is a non parametric test and it works for univariate and multivariate data. The p-value is currently computed only asymptotically (no bootstrap calibration at the moment).

Value

A list including:

p

The estimated probabiities.

lambda

The value of the Lagrangian parameter λ\lambda.

iters

The number of iterations required by the newton-Raphson algorithm.

info

The value of the log-likelihood ratio test statistic along with its corresponding p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Jing Bing-Yi and Andrew TA Wood (1996). Exponential empirical likelihood is not Bartlett correctable. Annals of Statistics 24(1): 365-369.

Owen A. B. (2001). Empirical likelihood. Chapman and Hall/CRC Press.

See Also

james, mv.eeltest2

Examples

x <- Rfast::rmvnorm(100, numeric(10), diag( rexp(10, 0.5) ) )
res<-mv.eeltest1(x, numeric(10) )

Exponential empirical likelihood hypothesis testing for two mean vectors

Description

Exponential empirical likelihood hypothesis testing for two mean vectors.

Usage

mv.eeltest2(y1, y2, tol = 1e-07, R = 0)

Arguments

y1

A matrix containing the Euclidean data of the first group.

y2

A matrix containing the Euclidean data of the second group.

tol

The tolerance level used to terminate the Newton-Raphson algorithm.

R

If R is 0, the classical chi-sqaure distribution is used, if R = 1, the corrected chi-square distribution (James, 1954) is used and if R = 2, the modified F distribution (Krishnamoorthy and Yanping, 2006) is used.

Details

Exponential empirical likelihood is a non parametric hypothesis testing procedure for one sample. The generalisation to two (or more samples) is via searching for the mean vector that minimises the sum of the two test statistics.

Value

A list including:

test

The empirical likelihood test statistic value.

modif.test

The modified test statistic, either via the chi-square or the F distribution.

pvalue

The p-value.

iters

The number of iterations required by the newton-Raphson algorithm.

mu

The estimated common mean vector.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Jing Bing-Yi and Andrew TA Wood (1996). Exponential empirical likelihood is not Bartlett correctable. Annals of Statistics 24(1): 365-369.

G.S. James (1954). Tests of Linear Hypothese in Univariate and Multivariate Analysis when the Ratios of the Population Variances are Unknown. Biometrika, 41(1/2): 19-43.

Krishnamoorthy K. and Yanping Xia (2006). On Selecting Tests for Equality of Two Normal Mean Vectors. Multivariate Behavioral Research 41(4): 533-548.

Owen A. B. (2001). Empirical likelihood. Chapman and Hall/CRC Press.

Amaral G.J.A., Dryden I.L. and Wood A.T.A. (2007). Pivotal bootstrap methods for k-sample problems in directional statistics and shape analysis. Journal of the American Statistical Association 102(478): 695-707.

Preston S.P. and Wood A.T.A. (2010). Two-Sample Bootstrap Hypothesis Tests for Three-Dimensional Labelled Landmark Data. Scandinavian Journal of Statistics 37(4): 568-587.

Tsagris M., Preston S. and Wood A.T.A. (2017). Nonparametric hypothesis testing for equality of means on the simplex. Journal of Statistical Computation and Simulation, 87(2): 406-422.

See Also

james, mv.eeltest1

Examples

res<-mv.eeltest2( as.matrix(iris[1:25, 1:4]), as.matrix(iris[26:50, 1:4]), R = 0 )
res<-mv.eeltest2( as.matrix(iris[1:25, 1:4]), as.matrix(iris[26:50, 1:4]), R = 1 )

Fast and general represantation of a factor variable

Description

Fast and general represantation of a factor variable.

Usage

ufactor(x)
## S3 method for class 'ufactor'
x[i]
## S3 method for class 'ufactor'
print(x,...)

Arguments

x

A vector with data.

i

An integer value/vector which is the index/indices to the element you want to access.

...

Anything the user want.

Details

This is a general implementation of factor structure. For access the fields of a "ufactor" use the "$" operator.

Value

An object of class "ufactor". This object holds 2 fields:

levels: the levels of the variable in his initial type values: the values of the variable in his initial type

Author(s)

Manos Papadakis

R implementation and documentation: and Manos Papadakis <[email protected]>.

See Also

colVars, factor

Examples

x <- rnorm(10)
R.factor<- as.factor(x)
Rfast.factor <- ufactor(x)

identical(levels(R.factor),Rfast.factor$levels) # TRUE
identical(as.numeric(R.factor),Rfast.factor$values) # TRUE
x<-R.factor<-Rfast.factor<-NULL

FBED variable selection method using the correlation

Description

FBED variable selection method using the correlation.

Usage

cor.fbed(y, x, ystand = TRUE, xstand = TRUE, alpha = 0.05, K = 0)

Arguments

y

The response variable, a numeric vector.

x

A matrix with the data, where the rows denote the samples and the columns are the variables.

ystand

If this is TRUE the response variable is centered. The mean is subtracted from every value.

xstand

If this is TRUE the independent variables are standardised.

alpha

The significance level, set to 0.05 by default.

K

The number of times to repeat the process. The default value is 0.

Details

FBED stands for Forward Backward with Earcly Dropping. It is a variation of the classical forward selection, where at each step, only the statistically significant variables carry on. The rest are dropped. The process stops when no other variables can be selected. If K = 1, the process is repeated testing sequentially again all those that have not been selected. If K > 1, then this is repeated.

In the end, the backward selection is performed to remove any falsely included variables. This backward phase has not been implemented yet.

Value

A list including:

runtime

The duration of the process.

res

A matrix with the index of the selected variable, their test statistic value and the associated p-value.

info

A matrix with two columns. The cumulative number of variables selected and the number of tests for each value of K.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Borboudakis G. and Tsamardinos I. (2019). Forward-backward selection with early dropping. Journal of Machine Learning Research, 20(8): 1-39.

See Also

cor.fsreg, ompr, correls, fs.reg

Examples

x <- matrnorm(100, 100)
y <- rnorm(100)
a <- cor.fbed(y, x)
a
x <- NULL

Find element

Description

Search a value in an unordered vector.

Usage

is_element(x, key)

Arguments

x

A vector or matrix with the data.

key

A value to check if exists in the vector x.

Details

Find if the key exists in the vector and return returns TRUE/FALSE if the value is been found. If the vector is unordered it is fast but if the vector is ordered then use binary_search. The functions is written in C++ in order to be as fast as possible.

Value

TRUE/FALSE if the value is been found.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

binary_search (buit-in R function)

Examples

x <- rnorm(500)
key <- x[50]
b <- is_element(x, key)

Find the given value in a hash table

Description

Find the given value in a hash table or list.

Usage

hash.find(x,key)

Arguments

x

A hash table or list.

key

The key for searching the table.

Details

This function search the given key.

Value

If the given key exists return its value else returns 0.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

hash.list

Examples

x <- hash.list(letters,c(1:26))
value <- hash.find(x,"a")
x[["a"]]==value

Fitted probabilities of the Terry-Bradley model

Description

Fitted probabilities of the Terry-Bradley model.

Usage

btmprobs(x, tol = 1e-09)

Arguments

x

A numerical square, usually not symmetric, matrix with discrete valued data. Each entry is a frequency, to give an example, the number of wins. x[i, j] is the number of wins of home team i against guest team j. x[j, i] is the number of wins of home team j against guest team i.

tol

The tolerance level to terminate the iterative algorithm.

Details

It fits a Bradley-Terry model to the given matrix and returns the fitted probabilities only.

Value

A list including:

iters

The numbetr of iterations required.

probs

A vector with probabilities which sum to 1. This is the probability of win for each item (or team in our hypothetical example).

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Bradley R.A. and Terry M.E. (1952). Rank Analysis of Incomplete Block Designs: I. The Method of Paired Comparisons. Biometrika, 39(3/4):324-345.

Huang Tzu-Kuo, Ruby C. Weng and Chih-Jen Lin (2006). Generalized Bradley-Terry models and multi-class probability estimates. Journal of Machine Learning Research, 7:85-115.

Agresti A. (2002). Categorical Data Analysis (2nd ed). New York: Wiley.

See Also

g2tests, poisson.anova, anova, poisson_only, poisson.mle

Examples

x <- matrix( rpois(10 * 10, 10), ncol = 10) ## not the best example though
res<-btmprobs(x)

Fitting a Dirichlet distribution via Newton-Rapshon

Description

Fitting a Dirichlet distribution via Newton-Rapshon.

Usage

diri.nr2(x, type = 1, tol = 1e-07)

Arguments

x

A matrix containing the compositional data. Zeros are not allowed.

type

Type 1 uses a vectorised version of the Newton-Raphson (Minka, 2012). In high dimensions this is to be preferred. If the data are too concentrated, regardless of the dimensions, this is also to be preferrred. Type 2 uses the regular Newton-Raphson, with matrix multiplications. In small dimensions this can be considerably faster.

tol

The tolerance level idicating no further increase in the log-likelihood.

Details

Maximum likelihood estimation of the parameters of a Dirichlet distribution is performed via Newton-Raphson. Initial values suggested by Minka (2012) are used.

Value

A list including:

loglik

The value of the log-likelihood.

param

The estimated parameters.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Minka Thomas (2012). Estimating a Dirichlet distribution. Technical report.

Ng Kai Wang, Guo-Liang Tian, and Man-Lai Tang (2011). Dirichlet and related distributions: Theory, methods and applications. John Wiley & Sons.

See Also

beta.mle

Examples

x <- matrix( rgamma(100 * 4, c(5, 6, 7, 8), 1), ncol = 4)
x <- x / rowsums(x)
res<-diri.nr2(x)

Floyd-Warshall algorithm for shortest paths in a directed graph

Description

Floyd-Warshall algorithm for shortest paths in a directed graph.

Usage

floyd(x)

Arguments

x

The adjacency matrix of a directed graph. A positive number (including) in x[i, j] indicates that there is an arrow from i to j and it also shows the cost of going from i to j. Hence, the algorithm will find not only the shortest path but also the with the smallest cost. A value of NA means that there is no path. Put positive number only, as negative will cause problems.

Details

The Floyd-Warshall algorithm is designed to find the shortest path (if it exists) between two nodes in a graph.

Value

A matrix, say z, with 0 and positive numbers. The elements denote the length of the shortest path between each pair of points. If z[i, j] is zero it means that there is no cost from i to j. If z[i, j] has a positive value it means that the length of going from i to j is equal to that value.

Author(s)

John Burkardt (C++ code)

Ported into R and documentation: Manos Papadakis <[email protected]>.

References

Floyd, Robert W. (1962). Algorithm 97: Shortest Path. Communications of the ACM. 5(6): 345.

Warshall, Stephen (1962). A theorem on Boolean matrices. Journal of the ACM. 9 (1): 11-12.

https://en.wikipedia.org/wiki/Floyd

See Also

colSort, rowSort

Examples

x <- matrix(NA, 10, 10)
x[sample(1:100, 10)] <- rpois(10, 3)
res<-floyd(x)

Variable selection in generalised linear regression models with forward selection

Description

Variable selection in generalised linear regression models with forward selection

Usage

fs.reg(y, ds, sig = 0.05, tol = 2, type = "logistic")

Arguments

y

The dependent variable. This can either be a binary numeric (0, 1) or a vector with integers (numeric or integer class), count data. The first case is for the binary logistic regression and the second for the Poisson regression.

ds

The dataset; provide a matrix where columns denote the variables and the rows the observations. The variables must be continuous, no categorical variables are accepted.

sig

Significance level for assessing the p-values significance. Default value is 0.05.

tol

The difference bewtween two successive values of the stopping rule. By default this is is set to 2. If for example, the BIC difference between two succesive models is less than 2, the process stops and the last variable, even though significant does not enter the model.

type

If you have a binary dependent variable, put "logistic" or "quasibinomial". If you have percentages, values between 0 and 1, including 0 and or 1, use "quasibinomial" as well. If you have count data put "poisson".

Details

The classical forward regression is implemented. The difference is that we have an extra step of check. Even if a variable is significant, the BIC of the model (with that variable) is calculated. If the decrease from the previous BIC (of the model without this variable) is less thatn a prespecified by the user value (default is 2) the variable wil enter. This way, we guard somehow against over-fitting.

Value

A matrix with for columns, the selected variables, the logarithm of their p-value, their test statistic and the BIC of the model with these variables included. If no variable is selected, the matrix is empty.

Author(s)

Marios Dimitriadis

Documentation: Marios Dimitriadis <[email protected]>.

See Also

cor.fsreg, logistic_only, poisson_only, glm_logistic, glm_poisson

Examples

set.seed(123)

#simulate a dataset with continuous data
x <- matrnorm(100, 50)
y <- rpois(100, 10)
a <- fs.reg(y, x, sig = 0.05, tol = 2, type = "poisson") 
x <- NULL

G-square test of conditional indepdence

Description

G-square test of conditional indepdence with and without permutations.

Usage

g2Test(data, x, y, cs, dc)
g2Test_perm(data, x, y, cs, dc, nperm)
chi2Test(data, x, y, cs, dc)

Arguments

data

A numerical matrix with the data. The minimum must be 0, otherwise the function can crash or will produce wrong results. The data must be consecutive numbers.

x

A number between 1 and the number of columns of data. This indicates which variable to take.

y

A number between 1 and the number of columns of data (other than x). This indicates the other variable whose independence with x is to be tested.

cs

A vector with the indices of the variables to condition upon. It must be non zero and between 1 and the number of variables. If you want unconditional independence test see g2Test_univariate and g2Test_univariate_perm. If there is an overlap between x, y and cs you will get 0 as the value of the test statistic.

dc

A numerical value equal to the number of variables (or columns of the data matrix) indicating the number of distinct, unique values (or levels) of each variable. Make sure you give the correct numbers here, otherwise the degrees of freedom will be wrong.

nperm

The number of permutations. The permutations test is slower than without permutations and should be used with small sample sizes or when the contigency tables have zeros. When there are few variables, R's "chisq.test" function is faster, but as the number of variables increase the time difference with R's procedure becomes larger and larger.

Details

The functions calculates the test statistic of the G2G^2 test of conditional independence between x and y conditional on a set of variable(s) cs.

Value

A list including:

statistic

The G2G^2 or chi2chi^2 test statistic.

df

The degrees of freedom of the test statistic.

x

The row or variable of the data.

y

The column or variable of the data.

Author(s)

Giorgos Borboudakis. The permutation version used a C++ code by John Burkardt.

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Tsamardinos, I., & Borboudakis, G. (2010). Permutation testing improves Bayesian network learning. In Joint European Conference on Machine Learning and Knowledge Discovery in Databases (pp. 322-337). Springer Berlin Heidelberg

See Also

g2Test_univariate, g2Test_univariate_perm, correls, univglms

Examples

nvalues <- 3
nvars <- 10
nsamples <- 5000
data <- matrix( sample( 0:(nvalues - 1), nvars * nsamples, replace = TRUE ), nsamples, nvars )
dc <- rep(nvalues, nvars)

res<-g2Test( data, 1, 2, 3, c(3, 3, 3) )
res<-g2Test_perm( data, 1, 2, 3, c(3, 3, 3), 1000 )

dc<-data<-NULL

Gamma regression with a log-link

Description

Gamma regression with a log-link.

Usage

gammareg(y, x, tol = 1e-07, maxiters = 100)
gammacon(y, tol = 1e-08, maxiters =50)

Arguments

y

The dependent variable, a numerical variable with non negative numbers.

x

A matrix or data.frame with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The maximum number of iterations that can take place in the regression.

Details

The gamma.reg fits a Gamma regression with a log-link. The gamma.con fits a Gamma regression with a log link with the intercept only ( glm(y ~ 1, Gamma(log) ) ).

Value

A list including:

deviance

The deviance value.

phi

The dispersion parameter (ϕ\phi) of the regression. This is necessary if you want to perform an F hypothesis test for the significance of one or more independent variables.

be

The regression coefficient(s).

info

The number of iterations, the deviance and the dispersion parameter.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris [email protected].

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

gammaregs, normlog.reg, invgauss.reg

Examples

y <- abs( rnorm(100) )
x <- matrix( rnorm(100 * 2), ncol = 2)
mod <- glm(y ~ x, family = Gamma(log) )
res<-summary(mod)

res<-gammareg(y, x)

mod <- glm(y ~ 1, family = Gamma(log) )
res<-summary(mod)
res<-gammacon(y)

Gaussian regression with a log-link

Description

Gaussian regression with a log-link.

Usage

normlog.reg(y, x, tol = 1e-07, maxiters = 100)

Arguments

y

The dependent variable, a numerical variable with non negative numbers.

x

A matrix or data.frame with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The maximum number of iterations that can take place in the regression.

Details

A Gaussian regression with a log-link is fitted.

Value

A list including:

i

The number of iterations required by the Newton-Raphson

loglik

The log-likelihood value.

deviance

The deviance value.

be

The regression coefficients

Author(s)

Stefanos Fafalios

R implementation and documentation: Stefanos Fafalios <[email protected]>

See Also

normlog.regs, score.glms, prop.regs, allbetas

Examples

y <- abs( rnorm(100) )
x <- matrix( rnorm(100 * 2), ncol = 2)
a <- normlog.reg(y, x)
b <- glm(y ~ x, family = gaussian(log) )
summary(b)
a

Generates random values from a normal and puts them in a matrix

Description

Generates random values from a normal and puts them in a matrix.

Usage

matrnorm(n, p, seed = NULL)

Arguments

n

The sample size, the number of rows the matrix will have.

p

The dimensionality of the data, the nubmer of columns of the matrix.

seed

If you want the same to be generated again use a seed for the generator, an integer number.

Details

How many times did you have to simulated data from a (standard) normal distribution in order to test something? For example, in order to see the speed of logistic_only, one needs to generate a matrix with predictor variables. The same is true for other similar functions. In sftests, one would like to examine the typer I error of this test under the null hypothesis.

By using the Ziggurat method of generating standard normal variates, this function is really fast when you want to generate big matrices.

Value

An n x p matrix with data simulated from a standard normal distribution.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

See Also

rvmf, Rnorm, rmvnorm, rvonmises

Examples

x <- matrnorm(100, 100)

Get specific columns/rows fo a matrix

Description

Get specific columns/rows of a matrix.

Usage

columns(x,indices)
rows(x,indices)

Arguments

x

A matrix with data.

indices

An integer vector with the indices.

Value

A matrix with the specific columns/rows of argumment indices.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowFalse, nth, colrange, colMedians, colVars, colSort, rowSort, rowTrue

Examples

x <- matrix(runif(100*100),100,100)
indices = sample(1:100,50)
all.equal(x[,indices],columns(x,indices))
all.equal(x[indices,],rows(x,indices))

x<-indices<-NULL

Hash - Pair function

Description

Hash - Pair function.

Usage

hash.list(key,x)

Arguments

key

The keys of the given values.

x

The values.

Details

This function pairs each item of of key and value make a unique hash table.

Value

Returns the hash-list table.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

hash.find

Examples

x <- hash.list(letters,c(1:26))
x[["a"]]==1

Hash object

Description

Hash object.

Usage

Hash(keys=NULL,values=NULL)
Hash.key.multi(x,...,sep = " ")
## S3 replacement method for class 'Hash'
x[...,sep = " "] <- value
## S3 method for class 'Hash'
x[...,sep = " "]
## S3 method for class 'Hash'
print(x,...)
## S3 method for class 'Hash'
length(x)

Arguments

x

A Hash object, using Hash function.

values

A vector with the values you want to store.

value

The values you want to store.

keys

A vector with keys for each values.

sep

A character value using to separate the multiple keys for each value.

...

One or more values for access or find elements.

Details

If you want to delete a key just insert the global variable "Rfast:::delete".

Hash: Create Hash object where every key has a value. Specify the type from the beggining (for speed). Use the argument "type" with one of the values "new.env, logical, character, integer, numeric". Hash.key.multi: search if key exists. If the keys are multiple, then use the argument "substr" to search inside each multiple for the specific key.

Value

A Hash object.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

hash.list, hash.find

Examples

x <- Hash(rnorm(10),sample(1:10))

x[1,2,13] <- 0.1234 # insert value using multi key. the same as x["1 2 13"] <- 0.1234
x[1,2,3] <- 15 # insert value using multi key. the same as x["1 2 3"] <- 15

Hash.key.multi(x,"1")
x # print Hash object using S3 generic
#x[1,2,3] <- Rfast:::delete # delete multi key. the same as x["1 2 3"] <- NULL
length(x)

Hash object to a list object

Description

Hash object to a list object.

Usage

hash2list(x, sorting = FALSE)

Arguments

x

A hash table with two parts, the keys (number(s) as string) and the key values (a single number).

sorting

This is if you you want the numbers in the keys sorted. The default value is FALSE.

Details

For every key, there is a key value. This function creates a list and puts every pair of keys and value in a component of a list.

Value

A list whose length is equal to the size of the hash table.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

hash.list, hash.find

Examples

x=list("1 2 4 3"=2.56,"2.34 1.05"=2)
res<-hash2list(x)
res<-hash2list(x,TRUE)

High dimensional MCD based detection of outliers

Description

High dimensional MCD based detection of outliers.

Usage

rmdp(y, alpha = 0.05, itertime = 100, parallel = FALSE)

Arguments

y

A matrix with numerical data with more columns (p) than rows (n), i.e. n<p.

alpha

The significance level, i.e. used to decide whether an observation is said to be considered a possible outlier. The default value is 0.05.

itertime

The number of iterations the algorithm will be ran. The higher the sample size, the larger this number must be. With 50 observations in R1000R^1000 maybe this has to be 1000 in order to produce stable results.

parallel

A logical value for parallel version.

Details

High dimensional outliers (n<<p) are detected using a properly constructed MCD. The variances of the variables are used and the determinant is simply their product.

Value

A list including: runtime = runtime, dis = dis, wei = wei

runtime

The duration of the process.

dis

The final estimated Mahalanobis type normalised distances.

wei

A bollean variable vector specifying whether an observation is "clean" (TRUE) or a possible outlier (FALSE).

cova

The estimated covatriance matrix.

Author(s)

Initial R code: Changliang Zou <[email protected]> R code modifications: Michail Tsagris <[email protected]> C++ implementation: Manos Papadakis <[email protected]> Documentation: Michail Tsagris <[email protected]> and Changliang Zhou <[email protected]>

References

Ro K., Zou C., Wang Z. and Yin G. (2015). Outlier detection for high-dimensional data. Biometrika, 102(3):589-599.

See Also

colmeans, colVars, colMedians

Examples

x <- matrix(rnorm(50 * 400), ncol = 400)
a <- rmdp(x, itertime = 500)

x<-a<-NULL

Hypothesis test for the distance correlation

Description

Hypothesis test for the distance correlation.

Usage

dcor.ttest(x, y, logged = FALSE)

Arguments

x

A numerical matrix.

y

A numerical matrix.

logged

Do you want the logarithm of the p-value to be returned? If yes, set this to TRUE.

Details

The bias corrected distance correlation is used. The hypothesis test is whether the two matrices are independent or not. Note, that this test is size correct as both the sample size and the dimensionality goes to infinity. It will not have the correct type I error for univariate data or for matrices with just a couple of variables.

Value

A vector with 4 elements, the bias corrected distance correlation, the degrees of freedom, the test statistic and its associated p-value.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

G.J. Szekely, M.L. Rizzo and N. K. Bakirov (2007). Measuring and Testing Independence by Correlation of Distances. Annals of Statistics, 35(6):2769-2794.

See Also

bcdcor, dcov, edist

Examples

x <- as.matrix(iris[1:50, 1:4])
y <- as.matrix(iris[51:100, 1:4])
res<-dcor.ttest(x, y)

Hypothesis test for two means of percentages

Description

Hypothesis test for two means of percentages.

Usage

percent.ttest(x, y, logged = FALSE)

Arguments

x

A numerical vector with the percentages of the first sample. Any value between 0 and 1 (inclusive) is allowed.

y

A numerical vector with the percentages of the first sample. Any value between 0 and 1 (inclusive) is allowed.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

This is the prop.reg but with a single categorical predictor which has two levels only. It is like a t-test for the means of two samples haivng percentages.

Value

A vector with three elements, the phi parameter, the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Papke L. E. & Wooldridge J. (1996). Econometric methods for fractional response variables with an application to 401(K) plan participation rates. Journal of Applied Econometrics, 11(6): 619-632.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

link{percent.ttests}, prop.reg, ttest2, ftest

Examples

x <- rbeta(100, 3, 1)
y <- rbeta(100, 7.5, 2.5)
res<-percent.ttest(x, y)

Hypothesis test for von Mises-Fisher distribution over Kent distribution

Description

The null hypothesis is whether a von Mises-Fisher distribution fits the data well, and the altenrative is that the Kent distribution is more suitable.

Usage

fish.kent(x, logged = FALSE)

Arguments

x

A numeric matrix containing the data as unit vectors in Euclidean coordinates.

logged

If you want the logarithm of the p-value ot be returned set this to TRUE.

Details

Essentially it is a test of rotational symmetry, whether Kent's ovalness parameter (beta) is equal to zero. This works for spherical data only.

Value

A vector with two elements, the value of the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Rivest, L. P. (1986). Modified Kent's statistics for testing goodness of fit for the Fisher distribution in small concentrated samples. Statistics & probability letters, 4(1): 1-4.

See Also

vmf.mle, iag.mle

Examples

x <- rvmf(100, rnorm(3), 15)
res<-fish.kent(x)
x <- NULL

Hypothesis testing between two skewness or kurtosis coefficients

Description

Hypothesis testing between two skewness or kurtosis coefficients.

Usage

skew.test2(x, y)

kurt.test2(x, y)

Arguments

x

A numerical vector with data.

y

A numerical vector with data, not necessarily of the same size.

Details

The skewness of kurtosis coefficients between two samples are being compared.

Value

A vector with the test statistic and its associated p-value.

Author(s)

Klio Lakiotaki

R implementation and documentation: Klio Lakiotaki <[email protected]>.

References

https://en.wikipedia.org/wiki/Skewness

https://en.wikipedia.org/wiki/Kurtosis

See Also

skew, colskewness, colmeans, colVars, colMedians

Examples

x <- rgamma(150,1, 4)
y <- rgamma(100, 1, 4)
res<-skew.test2(x, y)
res<-kurt.test2(x, y)

Index of the columns of a data.frame which are a specific type

Description

Index of the columns of a data.frame which are a specific type.

Usage

which.is(x,method="factor")

Arguments

x

A data.frame where some columns are expected to be factor variables.

method

A character value about the type. One of, "numeric","factor","integer","logical".

Details

The function is written in C++ and this is why it is very fast.

Value

A vector with the column indices which are factor variables. If there are no factor variables it will return an empty vector.

Author(s)

Manos Papadakis <[email protected]>

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

nth, Match

Examples

res<-which.is(iris)

Inverese Gaussian regression with a log-link

Description

Inverse Gaussian regression with a log-link.

Usage

invgauss.reg(y, x, tol = 1e-07, maxiters = 100)

Arguments

y

The dependent variable, a numerical variable with non negative numbers.

x

A matrix or data.frame with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The maximum number of iterations that can take place in the regression.

Details

An inverse Gaussian regression with a log-link is fitted.

Value

A list including:

i

The number of iterations required by the Newton-Raphson

loglik

The log-likelihood value.

deviance

The deviance value.

phi

The dispersion parameter (ϕ\phi) of the regression. This is necessary if you want to perform an F hypothesis test for the significance of one or more independent variables.

be

The regression coefficients

Author(s)

Michail Tsagris

R implementation and documentation: Stefanos Fafalios <[email protected]>

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

Zakariya Yahya Algamal and Intisar Ibrahim Allyas (2017). Prediction of blood lead level in maternal and fetal using generalized linear model. International Journal of Advanced Statistics and Probability, 5(2): 65-69.

See Also

invgauss.regs, normlog.reg, score.glms

Examples

y <- abs( rnorm(100) )
x <- matrix( rnorm(100 * 2), ncol = 2)
a <- invgauss.reg(y, x)
a

Inverse of a symmetric positive definite matrix

Description

Inverse of a symmetric positive definite matrix.

Usage

spdinv(A)

Arguments

A

A square positive definite matrix.

Details

After calculating the Cholesky decomposition of the matrix we use this upper triangular matrix to invert the original matrix.

Value

The inverse of the input matrix.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

http://econ.nsysu.edu.tw/ezfiles/124/1124/img/Chapter17_MaximumLikelihoodEstimation.pdf

See Also

cholesky, cova

Examples

s <- cova( as.matrix(iris[, 1:4]) )
res<-spdinv(s)
res<-solve(s)

Iterator

Description

A way to traverse a list, data.frame, matrix or vector.

Usage

iterator(x,method="ceil",type="vector",by=1)
## S3 method for class 'iterator'
print(x,...)
## S3 replacement method for class 'iterator'
Elem(x) <- value
Elem(x)
Elem(x) <- value
## S3 method for class 'iterator'
Elem(x)
## S3 method for class 'iterator'
x == y
## S3 method for class 'iterator'
x != y

Arguments

x

A variable with any type, or iterator object.

value

An value depending the method of the iterator.

y

An iterator.

method

Method of the iterator class. One of "ceil","col","row".

type

One of "vector","matrix","data.frame","list".

by

An integer value to iterate through element.

...

Anything the user want.

Details

iterator: is an object that helps a programmer to traverse the given object.

print.iterator: print an object of class iterator.

"Elem<-": access to element and change the value.

Elem: access to element.

Value

An object of class "iterator". This object holds 4 fields:

copy: deep copy of iterator. end: get iterator tha have access to points to the last element. equals: equality of iterators nextElem: move iterator to point to the next element using argument "by". prevElem: move iterator to point to the previous element using argument "by".

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans, read.directory

Examples

y<-rnorm(100)
x<-iterator(y,method="ceil",type="vector",by=1)

s<-0
while(x != x$end()){
	s <- s + Elem(x)
	x$nextElem()
}

all.equal(s,sum(y))

James multivariate version of the t-test

Description

James test for testing the equality of two population mean vectors without assuming equality of the covariance matrices.

Usage

james(y1, y2, a = 0.05, R = 1)

Arguments

y1

A matrix containing the Euclidean data of the first group.

y2

A matrix containing the Euclidean data of the second group.

a

The significance level, set to 0.05 by default.

R

If R is 1 the classical James test is returned. If R is 2 the MNV modficiation is implemented.

Details

Multivariate analysis of variance without assuming equality of the covariance matrices. The p-value can be calculated either asymptotically or via bootstrap. The James test (1954) or a modification proposed by Krishnamoorthy and Yanping (2006) is implemented. The James test uses a corected chi-square distribution, whereas the modified version uses an F distribution.

Value

A list including:

note

A message informing the user about the test used.

mesoi

The two mean vectors.

info

The test statistic, the p-value, the correction factor and the corrected critical value of the chi-square distribution if the James test has been used or, the test statistic, the p-value, the critical value and the degrees of freedom (numerator and denominator) of the F distribution if the modified James test has been used.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

G.S. James (1954). Tests of Linear Hypothese in Univariate and Multivariate Analysis when the Ratios of the Population Variances are Unknown. Biometrika, 41(1/2): 19-43

Krishnamoorthy K. and Yanping Xia. On Selecting Tests for Equality of Two Normal Mean Vectors (2006). Multivariate Behavioral Research 41(4): 533-548

See Also

mv.eeltest2

Examples

james( as.matrix(iris[1:25, 1:4]), as.matrix(iris[26:50, 1:4]), R = 1 )
james( as.matrix(iris[1:25, 1:4]), as.matrix(iris[26:50, 1:4]), R = 2 )

k nearest neighbours algorithm (k-NN)

Description

k nearest neighbours algorithm (k-NN).

Usage

knn(xnew, y, x, k, dist.type = "euclidean", type = "C", method = "average", 
freq.option = 0, mem.eff = FALSE)

Arguments

xnew

The new data, new predictor variable values. A matrix with numerical data.

y

A vector with the response variable, whose values for the new data we wish to predict. This can be numerical data, factor or discrete, 0, 1, ... The latter two cases are for classification.

x

The dataset. A matrix with numerical data.

k

The number of nearest neighbours to use. The number can either be a single value or a vector with multiple values.

dist.type

The type of distance to be used. Either \"euclidean\" or \"manhattan\".

type

If your response variable \"y\" is numerical data, then this should be \"R\" (regression). If \"y\" is in general categorical, factor or discrete set this argument to \"C\" (classification).

method

In case you have regression (type = \"R\") you want a way to summarise the prediction. If you want to take the average of the reponses of the k closest observations, type \"average\". For the median, type \"median\" and for the harmonic mean, type \"harmonic\".

freq.option

If classification (type = \"C\") and ties occur in the prediction, more than one class has the same number of k nearest neighbours, in which case there are two strategies available: Option 0 selects the first most frequent encountered. Option 1 randomly selects the most frequent value, in the case that there are duplicates.

mem.eff

Boolean value indicating a conservative or not use of memory. Lower usage of memory/Having this option on will lead to a slight decrease in execution speed and should ideally be on when the amount of memory in demand might be a concern.

Details

The concept behind k-NN is simple. Suppose we have a matrix with predictor variables and a vector with the response variable (numerical or categorical). When a new vector with observations (predictor variables) is available, its corresponding response value, numerical or category is to be predicted. Instead of using a model, parametric or not, one can use this ad hoc algorithm.

The k smallest distances between the new predictor variables and the existing ones are calculated. In the case of regression, the average, median or harmonic mean of the corresponding respone values of these closest predictor values are calculated. In the case of classification, i.e. categorical response value, a voting rule is applied. The most frequent group (response value) is where the new observation is to be allocated.

Value

A matrix whose number of columns is equal to the size of k. If in the input you provided there is just one value of k, then a matrix with one column is returned containing the predicted values. If more than one value was supplied, the matrix will contain the predicted values for every value of k.

Author(s)

Marios Dimitriadis

R implementation and documentation: Marios Dimitriadis <[email protected]>

References

Cover TM and Hart PE (1967). Nearest neighbor pattern classification. IEEE Transactions on Information Theory. 13(1):21-27.

Friedman J., Hastie T. and Tibshirani R. (2017). The elements of statistical learning. New York: Springer.

http://web.stanford.edu/~hastie/ElemStatLearn/printings/ESLII_print12.pdf

http://statlink.tripod.com/id3.html

See Also

knn.cv, dirknn, logistic_only, fs.reg, cor.fsreg

Examples

# Simulate a dataset with continuous data
x <- as.matrix(iris[, 1:4])
y <- as.numeric(iris[, 5])
id <- sample(1:150, 120)
mod <- knn(x[-id, ], y[id], x[id, ], k = c(4, 5, 6), type = "C", mem.eff = FALSE)
mod # Predicted values of y for 3 values of k. 
res<-table(mod[, 1], y[-id] )  # Confusion matrix for k = 4
res<-table(mod[, 2], y[-id] )  # Confusion matrix for k = 5
res<-table(mod[, 3], y[-id] )  # Confusion matrix for k = 6

k-NN algorithm using the arc cosinus distance

Description

It classifies new observations to some known groups via the k-NN algorithm.

Usage

dirknn(xnew, x, y, k, type = "C", parallel = FALSE)

Arguments

xnew

The new data whose membership is to be predicted, a numeric matrix with unit vectors. In case you have one vector only make it a row vector (i.e. matrix with one row).

x

The data, a numeric matrix with unit vectors.

k

The number of nearest neighbours. It can also be a vector with many values.

y

A numerical vector representing the class or label of each vector of x. 1, 2, 3, and so on. It can also be a numerical vector with data in order to perform regression.

type

If your response variable y is numerical data, then this should be "R" (regression) or "WR" for distance weighted based nearest neighbours. If y is in general categorical set this argument to "C" (classification) or to "WC" for distance weighted based nearest neighbours.

parallel

Do you want th ecalculations to take place in parallel? The default value is FALSE.

Details

The standard algorithm is to keep the k nearest observations and see the groups of these observations. The new observation is allocated to the most frequent seen group. The non standard algorithm is to calculate the classical mean or the harmonic mean of the k nearest observations for each group. The new observation is allocated to the group with the smallest mean distance.

If you want regression, the predicted value is calculated as the average of the responses of the k nearest observations.

Value

A matrix with the predicted group(s). It has as many columns as the values of k.

Author(s)

Stefanos Fafalios

R implementation and documentation: Stefanos Fafalios <[email protected]>

See Also

dirknn.cv, knn, vmf.mle, spml.mle

Examples

x <- as.matrix(iris[, 1:4])
x <- x/sqrt( rowSums(x^2) )
y<- as.numeric( iris[, 5] )
a <- dirknn(x, x, y, k = 2:10)

Limited number of eigenvalues and eigenvectors of a symmetric matrix

Description

Limited number of eigenvalues and eigenvectors of a symmetric matrix.

Usage

eigen.sym(A, k, vectors = TRUE)

Arguments

A

A symmetric matrix.

k

The number of eigenvalues and eigenvectors to extract.

vectors

A flag that indicates if the eigenvectors will be returned (default: vectors = True)

Details

The function calls the same function from the Armadillo library in C++. It is quite faster than R's built in function "eigen" if the number of eigenvalues and eigenvectors (argument k) is small.

The k largest, in magnitude, eigenvalues are returned. Hence, if the matrix is not positive definite you may get negative eigenvalues as well. So, it is advised to use it with positive definite matrices.

Value

A list including:

values

The eigenvalues.

vectors

The eigenvectors.

Author(s)

Armadillo library in C++ and Stefanos Fafalios and Manos Papadakis.

R implementation and documentation: Stefanos Fafalios <[email protected]> and Manos Papadakis <[email protected]>.

See Also

hd.eigen

Examples

x <- matrnorm(500, 100 )
s <- Rfast::cova(x)
res<-eigen.sym(s, 5)
x <- s <- NULL

Linear models for large scale data

Description

Linear models for large scale data.

Usage

lmfit(x, y, w = NULL)

Arguments

x

The design matrix with the data, where each column refers to a different sample of subjects. You must supply the design matrix, with the column of 1s. This function is the analogue of lm.fit and .lm.fit.

y

A numerical vector or a numerical matrix.

w

An optional numerical vector with weights. Note that if you supply this, the function does not make them sum to 1. So, you should do it.

Details

We have simply exploitted R's powerful function and managed to do better than .lm.fit which is a really powerful function as well. This is a bare bones function as it returns only two things, the coefficients and the residuals. .lm.fit returns more and lm.fit even more and finally lm returns too much. The motivatrion came form this site https://m-clark.github.io/docs/fastr.html . We changed the function a bit.

Value

A list including:

be

The beta coefficients.

residuals

The residuals of the linear model(s).

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

See Also

regression, allbetas, correls, mvbetas, cor.fsreg

Examples

n <- 200  ;  p <- 5
X <- matrnorm(n, p)
y <- rnorm(n)
a1 <- .lm.fit(X, y) 
a2 <- lmfit(X, y) 
x <- NULL

Logistic and Poisson regression models

Description

Logistic and Poisson regression models.

Usage

glm_logistic(x, y, full = FALSE,tol = 1e-09, maxiters = 100)
glm_poisson(x, y, full = FALSE,tol = 1e-09)

Arguments

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. This can be a matrix or a data.frame (with factors).

y

The dependent variable; a numerical vector with two values (0 and 1) for the logistic regression or integer values, 0, 1, 2,... for the Poisson regression.

full

If this is FALSE, the coefficients and the deviance will be returned only. If this is TRUE, more information is returned.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The max number of iterations that can take place in each regression.

Details

The function is written in C++ and this is why it is very fast.

Value

When full is FALSE a list including:

be

The regression coefficients.

devi

The deviance of the model.

When full is TRUE a list including:

info

The regression coefficients, their standard error, their Wald test statistic and their p-value.

devi

The deviance.

Author(s)

Manos Papadakis <[email protected]>

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

poisson_only, logistic_only, univglms, regression

Examples

x <- matrix(rnorm(100 * 3), ncol = 3)
y <- rbinom(100, 1, 0.6)   ## binary logistic regression
a1 <- glm_logistic(x, y, full = TRUE) 
a2 <- glm(y ~ x, binomial)

x <- matrix(rnorm(100 * 3), ncol = 3)
y <- rpois(100, 10)   ## binary logistic regression
b1 <- glm_poisson(x, y, full = TRUE) 
b2 <- glm(y ~ x, poisson)

x<-y<-a1<-a2<-b1<-b2<-NULL

Logistic or Poisson regression with a single categorical predictor

Description

Logistic or Poisson regression with a single categorical predictor.

Usage

logistic.cat1(y, x, logged = FALSE)
poisson.cat1(y, x, logged = FALSE)

Arguments

y

A numerical vector with values 0 or 1.

x

A numerical vector with discrete numbers or a factor variable. This is suppose to be a categorical predictor. If you supply a continuous valued vector the function will obviously provide wrong results. Note: For the "binomial.anova" if this is a numerical vector it must contain strictly positive numbers, i.e. 1, 2, 3, 4, ..., no zeros are allowed.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

There is a closed form solution for the logistic regression in the case of a single predictor variable. See the references for more information.

Value

info

A matrix similar to the one produced by the glm command. The estimates, their standard error, the Wald value and the relevant p-value.

devs

For the logistic regression case a vector with the null and the residual deviances, their difference and the significance of this difference.

res

For the Poisson regression case a vector with the log likelihood ratio test statistic value and its significance.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Stan Lipovetsky (2015). Analytical closed-form solution for binary logit regression by categorical predictors. Journal of Applied Statistics, 42(1): 37–49.

See Also

poisson.anova, poisson.anovas, anova, logistic_only, poisson_only

Examples

y <- rbinom(20000, 1, 0.6)
x <- as.factor( rbinom(20000, 3, 0.5) )
a1 <- logistic.cat1(y, x)
#a2 <- glm(y ~ x, binomial) 

y <- rpois(20000, 10)
x <- as.factor( rbinom(20000, 3, 0.5) )
a1 <- poisson.cat1(y, x)
#a2 <- glm(y ~ x, poisson) 

x<-y<-a1<-a2<-NULL

Mahalanobis distance

Description

Mahalanobis distance.

Usage

mahala(x, mu, sigma, ischol = FALSE)

Arguments

x

A matrix with the data, where rows denotes observations (vectors) and the columns contain the variables.

mu

The mean vector.

sigma

The covariance or any square symmetric matrix.

ischol

A boolean variable set to true if the Cholesky decomposition of the covariance matrix is supplied in the argument \"sigma\".

Value

A vector with the Mahalanobis distances.

Author(s)

Matteo Fasiolo <[email protected]>,

C++ and R implementation and documentation: Matteo Fasiolo <[email protected]>.

See Also

dista, colmeans

Examples

x <- matrix( rnorm(100 * 50), ncol = 50 )
m <- colmeans(x)
s <- cov(x)
a1 <- mahala(x, m, s)

Many area under the curve values

Description

Many area under the curve values.

Usage

colaucs(group, preds)
auc(group, preds)

Arguments

group

A numerical vector with two values, one of which must be strictly 1.

preds

A numerical matrix with scores, probabilities or any other measure. In the case of auc this is a vector.

Details

The AUCs are calculated column-wise or just an AUC if the vector function is used.

Value

A vector with length equal to the number of columns of the "preds" argument, with the AUC values for each column. If the "auc" function is used then a signle number is returned.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

ttests, ttest, ftests

Examples

## 200 variables, hence 200 AUCs will be calculated
x <- matrix( rnorm(100 * 200), ncol = 200 )
ina <- rbinom(100, 1, 0.6)
colaucs(ina, x)
a <- colaucs(ina, x) 
b <- auc(ina, x[, 1])
x <- NULL

Many 2 sample proportions tests

Description

It performs very many 2 sample proportions tests.

Usage

proptests(x1, x2, n1, n2)

Arguments

x1

A vector with the successes of the one group.

x2

A vector with the successes of the one group.

n1

A vector with the number of trials of the one group.

n2

A vector with the number of trials of the one group.

Details

The 2-sample proportions test is performed for each pair of proportions of teh two groups.

Value

A matrix with the proportions of each group (two columns), the test statistic and the p-value of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

B. L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

See Also

ttests, ftests, colVars

Examples

## 10000 variables, hence 10000 t-tests will be performed
set.seed(12345)
x1 <- rpois(500, 5)
x2 <- rpois(500, 5)
n1 <- rpois(1000, 40)
n2 <- rpois(1000, 40)
a <- proptests(x1, x2, n1, n2)
mean(a[, 4]<0.05)

x1 <- rbinom(500, 500, 0.6)
x2 <- rbinom(500, 500, 0.6)
b <- proptests(x1, x2, 500, 500)
mean(b[, 4]<0.05)

Many 2 sample tests tests

Description

It performs very many 2 sample tests.

Usage

ttests(x, y = NULL, ina, paired = FALSE, logged = FALSE, parallel = FALSE)
mcnemars(x, y = NULL, ina, logged = FALSE) 
var2tests(x, y = NULL, ina, alternative = "unequal", logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the samples and the columns are the variables.

y

A second matrix with the data of the second group. If this is NULL (default value) then the argument ina must be supplied. Notice that when you supply the two matrices the procedure is two times faster.

ina

A numerical vector with 1s and 2s indicating the two groups. Be careful, the function is designed to accept only these two numbers. In addition, if your "y" is NULL, you must specify "ina".

alternative

The type of hypothesis to be checked, "equal", "greater", "less".

paired

If the groups are not independent paired t-tests should be performed and this must be TRUE, otherwise, leave it FALSE. In this case, the two groups must have equal smaple sizes, otherwise no test will be performed.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

parallel

Should parallel implentations take place in C++? The default value is FALSE.

Details

For the ttests, if the groups are independent, the Welch's t-test (without assuming equal variances) is performed. Otherwise many paired t-tests are performed. The McNemar's test requires a number of observations, at least 30 would be good in order for the test to have some power and be size corect.

Value

A matrix with the test statistic, the degrees of freedom (if the groups are independent) and the p-value (or their logarithm) of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

B. L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

McNemar Q. (1947). Note on the sampling error of the difference between correlated proportions or percentages. Psychometrika. 12(2):153-157.

See Also

ftests, anovas, ttest

Examples

## 1000 variables, hence 1000 t-tests will be performed
x = matrnorm(100, 100)
## 100 observations in total
ina = rbinom(100, 1, 0.6) + 1   ## independent samples t-test
ttests(x, ina = ina)
x1 = x[ina == 1, ]
x2 = x[ina == 2, ]
ttests(x1, x2)
x <- NULL

Many analysis of variance tests with a discrete variable

Description

Many analysis of variance tests with a discrete variable.

Usage

poisson.anovas(y, ina, logged = FALSE) 
quasipoisson.anovas(y, ina, logged = FALSE)
geom.anovas(y, ina, type = 1, logged = FALSE)

Arguments

y

A numerical matrix with discrete valued data, i.e. counts for the case of the Poisson, or with 0s and 1s for the case of the Bernoulli distribution. Each column represents a variable.

ina

A numerical vector with discrete numbers starting from 1, i.e. 1, 2, 3, 4,... or a factor variable. This is suppose to be a categorical predictor. If you supply a continuous valued vector the function will obviously provide wrong results.

type

This rgument is for the geometric distribution. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

This is the analysis of variance with count data. What we do is many log-likelihood ratio tests. For the quasi Poisson case we scale the difference in the deviances.

Value

A matrix with two values, the difference in the deviances (test statistic) and the relevant p-value. For the case of quasi Poisson the estimated ϕ\phi parameter is also returned.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

g2tests, poisson.anova, anova, poisson_only, poisson.mle

Examples

ina <- rbinom(500, 3, 0.5) + 1 
## Poisson example
y <- matrix( rpois(500 * 100, 10), ncol= 100 )
a1 <- poisson.anovas(y, ina)
y <- NULL

Many ANCOVAs

Description

Many ANCOVAs.

Usage

ancovas(y, ina, x, logged = FALSE)

Arguments

y

A matrix with the data, where the rows denote the observations and the columns are the variables.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero.

x

A numerical vector whose length is equal to the number of rows of y. This is the covariate.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

Many Analysis of covariance tests are performed. No interaction between the factor and the covariate is tested. Only the main effects. The design need not be balanced. The values of ina need not have the same frequency. The sums of squares have been adjusted to accept balanced and unbalanced designs.

Value

A matrix with the test statistic and the p-value for the factor variable and the covariate.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

D.C. Montgomery (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons

See Also

ftests, ttests, anovas

Examples

## 100 variables, hence 100 F-tests will be performed
y <- matrix( rnorm(90 * 100), ncol = 100 )
ina <- rbinom(90, 2, 0.5) + 1
x <- rnorm(90)
a <- ancovas(y, ina, x)

m1 <- lm(y[, 15] ~ factor(ina) + x)
m2 <- lm(y[, 15] ~ x + factor(ina))
res<-anova(m1)
res<-anova(m2)
y <- NULL
a[15, ]  ## the same with the m2 model, but not the m1

Many ANOVAS for count data with Poisson or quasi Poisson models

Description

Many ANOVAS for count data with Poisson or quasi Poisson models.

Usage

colpoisson.anovas(y, x, logged = FALSE) 
colquasipoisson.anovas(y, x, logged = FALSE)

Arguments

y

A numerical vector with the data.

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. This must be a matrix with the categorical variables as numbers, starting from 1. Poisson or quassi Poisson ANOVA takes place for each column.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Details

Poisson or quassi Poisson ANOVA takes place at each column.

Value

A matrix with the test statistic and the (logged) p-value for each predictor variable. In the case of the quasi Poisson, the ϕ\phi is returned as well.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

See Also

poisson.anova boot.ttest2, ttest2, ftest

Examples

y <- rpois(200, 10)
x <- matrix(rbinom(200 * 10, 3, 0.5 ), ncol = 10)

Many exponential regressions

Description

Many exponential regressions.

Usage

expregs(y, x, di, tol = 1e-09, logged = FALSE)

Arguments

y

A vector with positive data (including zeros).

x

A numerical matrix with the predictor variables.

di

A vector of size equal to that of y with 0s and 1s indicating censoring or not respectively.

tol

The tolerance value to stop the newton-Raphson iterations. It is set to 1e-09 by default.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Details

We have implemented the newton-Raphson in order to avoid unnecessary calculations.

Value

A matrix with three columns, the test statistic, its associated (logged) p-value and the BIC of each model.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

univglms, score.glms, logistic_only, poisson_only, regression

Examples

## 200 variables, hence 200 univariate regressions are to be fitted
x <- matrnorm(100, 100)
y <- rexp(100, 4)
expregs(y, x, di = rep(1, length(y)))
x <- NULL

Many F-tests with really huge matrices

Description

Many F-tests with really huge matrices.

Usage

list.ftests(x, logged = FALSE)

Arguments

x

A list with many big size matrices. Each element of the list contains a matrix. This is the ftests function but with really huge matrices, which cannot be loaded into R as a single matrix.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The Welch's F-test (without assuming equal variances) is performed just like in the "ftests" function. The difference is that you have a really huge matrix which you cannot load into R. In the "ftests" function, the argument "ina" denotes the different groups. Here, you "cut" the matrix into smaller ones, each of which denotes a different group and put them in a list.

Value

A matrix with the test statistic and the p-value of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

B.L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

See Also

ftests, ttests

Examples

x <- matrnorm(300, 500)
ina <- rbinom(300, 2, 0.6) + 1
a <- list()
a[[ 1 ]] <- x[ina == 1, ]
a[[ 2 ]] <- x[ina == 2, ]
a[[ 3 ]] <- x[ina == 3, ]
mod <- list.ftests(a)
z <- NULL
a <- NULL

Many G-square tests of indepedence

Description

Many G-square tests of indepdence with and without permutations.

Usage

g2tests(data, x, y, dc)
g2tests_perm(data, x, y, dc, nperm) 
chi2tests(data, x, y, dc)

Arguments

data

A numerical matrix with the data. The minimum must be 0, otherwise the function can crash or will produce wrong results. The data must be consecutive numbers.

x

An integer number or a vector of integer numbers showing the other variable(s) to be used for the G2G^2 test of independence.

y

An integer number showing which column of data to be used.

dc

A numerical value equal to the number of variables (or columns of the data matrix) indicating the number of distinct, unique values (or levels) of each variable. Make sure you give the correct numbers here, otherwise the degrees of freedom will be wrong.

nperm

The number of permutations. The permutations test is slower than without permutations and should be used with small sample sizes or when the contigency tables have zeros. When there are few variables, R's "chisq.test" function is faster, but as the number of variables increase the time difference with R's procedure becomes larger and larger.

Details

The function does all the pairwise G2G^2 test of independence and gives the position inside the matrix. The user must build the associations matrix now, similarly to the correlation matrix. See the examples of how to do that. The p-value is not returned, we leave this to the user. See the examples of how to obtain it.

Value

A list including:

statistic

The G2G^2 or χ2\chi^2 test statistic for each pair of variables.

pvalue

This is returned when you have selected the permutation based G2G^2 test.

x

The row or variable of the data.

y

The column or variable of the data.

df

The degrees of freedom of each test.

Author(s)

Giorgos Borboudakis. The permutation version used a C++ code by John Burkardt.

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Tsagris M. (2017). Conditional independence test for categorical data using Poisson log-linear model. Journal of Data Science, 15(2):347-356.

Tsamardinos, I., & Borboudakis, G. (2010). Permutation testing improves Bayesian network learning. In Joint European Conference on Machine Learning and Knowledge Discovery in Databases (pp. 322-337). Springer Berlin Heidelberg.

See Also

g2Test, g2Test_perm, correls, univglms

Examples

nvalues <- 3
nvars <- 10
nsamples <- 2000
data <- matrix( sample( 0:(nvalues - 1), nvars * nsamples, replace = TRUE ), nsamples, nvars )
dc <- rep(nvalues, nvars)
a <- g2tests(data = data, x = 2:9, y = 1, dc = dc)
pval <- pchisq(a$statistic, a$df, lower.tail = FALSE)  ## p-value
b <- g2tests_perm(data = data, x = 2:9, y = 1, dc = dc, nperm = 1000)
a<-b<-data<-NULL

Many Gini coefficients

Description

Many Gini coefficients.

Usage

ginis(x)

Arguments

x

A matrix with non negative data. The rows are observations and the columns denote the variables.

Details

We have implemented the fast version of the Gini coefficient. See wikipedia for more details.

Value

A vector with the Gini coefficient, one for each variable.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colskewness, colmeans, corpairs

Examples

x <- matrix( rpois(500 * 1000, 1000), ncol = 1000 )
a <- ginis(x)

Many hypothesis tests for two means of percentages

Description

Many hypothesis tests for two means of percentages.

Usage

percent.ttests(x, y, logged = FALSE)

Arguments

x

A numericalmatrix with the percentages of the first sample. Any value between 0 and 1 (inclusive) is allowed.

y

A numerical matrix with the percentages of the first sample. Any value between 0 and 1 (inclusive) is allowed.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

This is the prop.reg but with a single categorical predictor which has two levels only. It is like a t-test for the means of two samples haivng percentages.

Value

A matrix with three columns, the phi parameter, the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Papke L. E. & Wooldridge J. (1996). Econometric methods for fractional response variables with an application to 401(K) plan participation rates. Journal of Applied Econometrics, 11(6): 619-632.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

link{percent.ttest}, prop.reg, ttest2, ftest

Examples

x <- matrix( rbeta(100 * 10, 3, 1), ncol = 10)
y <- matrix( rbeta(50 * 10, 7.5, 2.5), ncol = 10)
res<-percent.ttests(x, y)

Many moment and maximum likelihood estimations of variance components

Description

Many moment and maximum likelihood estimations of variance components.

Usage

colvarcomps.mom(x, id, parallel = FALSE) 
colvarcomps.mle(x, id, ranef = FALSE, tol= 1e-08, maxiters = 100, 
parallel = FALSE)

Arguments

x

A matrix with the data, where each column refers to a different sample of subjects.

id

A numerical vector indicating the subject. You must put consecutive numbers and no zero values. Alternatively this can be a factor variable.

ranef

Do you also want the random effects to be returned? TRUE or FALSE.

tol

The tolerance level to terminate the golden ratio search.

maxiters

The maximum number of iterations to perform.

parallel

Should the computations run in parallel? TRUE or FALSE.

Details

Note that the "colvarcomp.mom" works for balanced designs only, i.e. for each subject the same number of measurements have been taken. The "colvarcomps.mle" works for unbalanced as well.

The variance components, the variance of the between measurements and the variance of the within are estimated using moment estimators. The "colvarcomps.mom" is the moment analogue of a random effects model which uses likelihood estimation ("colvarcomps.mle"). It is much faster, but can give negative variance of the random effects, in which case it becomes zero.

The maximum likelihood version is a bit slower (try youselves to see the difference), but statistically speaking is to be preferred when small samples are available. The reason why it is only a little bit slower and not a lot slower as one would imagine is because we are using a closed formula to calculate the two variance components (Demidenko, 2013, pg. 67-69). Yes, there are closed formulas for linear mixed models.

Value

For the "colvarcomps.mom": A matrix with 5 columns, The MSE, the estimate of the between variance, the variance components ratio and a 95% confidence for the ratio.

For the "colvarcomps.mle": If ranef = FALSE a list with a single component called "info". That is a matrix with 3 columns, The MSE, the estimate of the between variance and the log-likelihood value. If ranef = TRUE a list including "info" and an extra component called "ranef" containing the random effects. It is a matrix with the same number of columns as the data. Each column contains the randome effects of each variable.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

D.C. Montgomery (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons.

Charles S. Davis (2002). Statistical methods for the analysis of repeated measures. New York: Springer-Verlag.

Demidenko E. (2013). Mixed Models: Thoery and Applications with R 2nd Edition). New Jersey: John Wiley & Sons (Excellent book).

See Also

varcomps.mle, colrint.regbx

Examples

## example taken from Montgomery, page 514-517.
y <- c(98, 97, 99, 96, 91, 90, 93, 92,
96, 95, 97, 95, 95, 96, 99, 98)
y <- matrix(y)
id <- rep(1:4, each = 4)

x <- rmvnorm(100, numeric(100), diag(rexp(100)) )
id <- rep(1:25, each = 4)
n <- 25  ;  d <- 4
a <- colvarcomps.mom(x, id) 
mean(a[, 4]<0 & a[, 5]>0)  
b <- colvarcomps.mle(x, id) 
x <- NULL

Many multi-sample tests

Description

Many multi-sample tests.

Usage

ftests(x, ina, logged = FALSE)
anovas(x, ina, logged = FALSE)
vartests(x, ina, type = "levene", logged = FALSE)
block.anovas(x, treat, block, logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the observations (and the two groups) and the columns are the variables.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero. Alternatively it can be a factor variable.

type

This is for the variances test and can be either "levene" or "bf" corresponding to Levene's or Brown-Forsythe's testing procedure.

treat

In the case of the blocking ANOVA this argument plays the role of the "ina" argument.

block

This item, in the blocking ANOVA denotes the subjects which are the same. Similarly to "ina" a numeric vector with 1s, 2s, 3s and so on.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The Welch's F-test (without assuming equal variances) is performed with the "ftests" function. The "anovas" function perform the classical (Fisher's) one-way analysis of variance (ANOVA) which assumes equal variance across the groups.

The "vartests" perform hypothesis test for the equality of the variances in two ways, either via the Levene or via the Brown-Forshythe procedure. Levene's test employs the means, whereas the Brown-Forsythe procedure employs the medians and is therefore more robust to outliers. The "var2tests" implement the classical F test.

The "block.anova" is the ANOVA with blocking, randomised complete block design (RCBD). In this case, for every combination of the block and treatment values, there is only one observation. The mathematics are the same as in the case of two way ANOVA, but the assumptions different and the testing procedure also different. In addition, no interaction is present.

Value

A matrix with the test statistic and the p-value of each test.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Welch B.L. (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

Montgomery D.C. (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons.

See Also

ttests

Examples

x <- matrix( rnorm(300 * 50), ncol = 50 )
## 300 observations in total
ina <- rbinom(300, 3, 0.6) + 1   
a1 <- ftests(x, ina) 
a2 <- anovas(x, ina) 
a3 <- vartests(x, ina) 
x <- NULL

Many multivariate simple linear regressions coefficients

Description

Many multivariate simple linear regressions coefficients.

Usage

mvbetas(y, x, pvalue = FALSE)

Arguments

y

A matrix with the data, where rows denotes the observations and the columns contain the dependent variables.

x

A numerical vector with one continuous independent variable only.

pvalue

If you want a hypothesis test that each slope (beta coefficient) is equal to zero set this equal to TRUE. It will also produce all the correlations between y and x.

Details

It is a function somehow opposite to the allbetas. Instead of having one y and many xs we have many ys and one x.

Value

A matrix with the constant (alpha) and the slope (beta) for each simple linear regression. If the p-value is set to TRUE, the correlation of each y with the x is calculated along with the relevant p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

allbetas, correls, univglms

Examples

y <- matrnorm(100, 100)
x <- rnorm(100)
a <- mvbetas(y, x, pvalue = FALSE)
b <- matrix(nrow = 100, ncol = 2)
z <- cbind(1, x)

a <- mvbetas(y, x)
b[2, ] <- coef( lm.fit( z, y[, 1] ) )
b[2, ] <- coef( lm.fit( z, y[, 2] ) )
x <- NULL

Many multi-sample tests

Description

Many multi-sample tests.

Usage

kruskaltests(x, ina, logged = FALSE) 
cqtests(x, treat, block, logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero.

treat

In the case of the Cochran's Q test, this argument plays the role of the "ina" argument.

block

This item denotes the subjects which are the same. Similarly to "ina" a numeric vector with 1s, 2s, 3s and so on.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The "kruskaltests" performs the Kruskal-Wallis non parametric alternative to analysis of variance test. The "cqtests" performs the Cocrhan's Q test for the equality of more than two groups whose values are strictly binary (0 or 1). This is a generalisation of the McNemar's test in the multi-sample case.

Value

A matrix with the test statistic and the p-value of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

block.anovas, ftests

Examples

x <- matrix( rexp(300 * 200), ncol = 200 )
ina <- rbinom(300, 3, 0.6) + 1   
kruskaltests(x, ina)
x <- matrix( rbinom(300 * 200, 1, 0.6), ncol = 200 )
treat <- rep(1:3, each = 100)
block <- rep(1:3, 100)  
cqtests(x, treat, block)
x <- NULL

Many odds ratio tests

Description

It performs very many odds ratio tests.

Usage

odds(x, y = NULL, ina, logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the observations and the columns are the variables. They must be 0s and 1s only.

y

A second matrix with the data of the second group. If this is NULL (default value) then the argument ina must be supplied. Notice that when you supply the two matrices the procedure is two times faster. They must be 0s and 1s only.

ina

A numerical vector with 1s and 2s indicating the two groups. Be careful, the function is designed to accept only these two numbers. In addition, if your "y" is NULL, you must specify "ina".

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

Many odds ratio tests are performed.

Value

A matrix with the test statistic and the p-value (or their logarithm) of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Mosteller Frederick (1968). Association and Estimation in Contingency Tables. Journal of the American Statistical Association. 63(321):1-28.

Edwards A.W.F. (1963). The measure of association in a 2x2 table. Journal of the Royal Statistical Society, Series A. 126(1):109-114.

See Also

odds.ratio, g2Test_univariate

Examples

x <- matrix( rbinom(100 * 100, 1, 0.5), ncol = 100 )
ina <- rep(1:2, each = 50)
a <- odds(x, ina = ina)

Many one sample goodness of fit tests for categorical data

Description

Many one sample goodness of fit tests for categorical data.

Usage

cat.goftests(x, props, type = "gsquare", logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the samples and the columns are the variables. The data must be integers and be of the form 1, 2, 3, and so on. The minimum must be 1, and not zero.

props

The assumed distribution of the data. A vector or percentages summing to 1.

type

Either Pearson's χ2\chi^2 test ("chisquare") is used or the G2G^2 test ("qsquare", default value).

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

Given a matrix of integers, where each column refers to a sample, the values of a categorical variable the function tests wether these values can be assumed to fit a specific distribution.

Value

A matrix with the test statistic and the p-value of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

ttests, ttest, ftests

Examples

x <- matrix( rbinom(300 * 100, 4, 0.6), ncol = 100 ) + 1
props <- dbinom(0:4, 4, 0.6)
## can we assume that each column comes from a distribution  whose mass is given by props?
cat.goftests(x, props)
a1 <- cat.goftests(x, props)  ## G-square test
a2 <- cat.goftests(x, props, type = "chisq")  ## Chi-square test
cor(a1, a2)
mean( abs(a1 - a2) ) 
x <- NULL

Many one sample tests

Description

Many one sample tests.

Usage

proptest(x, n, p, alternative = "unequal", logged = FALSE) 
ttest(x, m, alternative = "unequal", logged = FALSE, conf = NULL)
vartest(x, sigma, alternative = "unequal", logged = FALSE, conf = NULL)

Arguments

x

A matrix with numerical data. Each column of the matrix corresponds to a sample, or a group. In the case of the "proptest" this is a vector integers ranging from 0 up to n. It is the number of "successes".

n

This is for the "proptest" only and is a vector with integer numbers specifying the number of tries for the proptest. Its size is equal to the size of x.

p

A vector with the assumed probabilities of success in the "proptest". Its size is equal to the number of colums of the matrix x.

m

A vector with the assumed means. Its size is equal to the number of colums of the matrix x.

sigma

A vector with assumed variances. Its size is equal to the number of colums of the matrix x.

alternative

The type of hypothesis to be checked. Equal to ("unequal"), grater than("greater") or less than ("less") the assumed parameter.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

conf

If you want confidence intervals to be returned specify the confidence level, otherwise leave it NULL.

Details

Despite the functions having been written in R, they are very fast.

Value

For all tests except for the "sftests" a matrix with two colums, the test statistic and the p-value respectively.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

ftests, ttests

Examples

R <- 100
## protest
x <- rbinom(R, 50, 0.6)
n <- rep(50, R)
p <- rep(0.6, R)
a1 <- proptest(x, n, p, "unequal", logged = FALSE)
res<-sum( a1[, 2] < 0.05 ) / R

## vartest
x <- matrnorm(100, 100)
a2 <- vartest(x, rep(1, R) )
res<-sum( a2[, 2] < 0.05 )

## ttest
a4 <- ttest(x, numeric(R) )
res<-sum(a4[, 2] < 0.05) / R
x <- NULL

Many random intercepts LMMs for balanced data with a single identical covariate

Description

Many random intercepts LMMs for balanced data with a single identical covariate.

Usage

colrint.regbx(y, x, id)

Arguments

y

A numerical matrix with the data. The subject values.

x

A numerical vector with the same length as the number of rows of y indicating the fixed predictor variable. Its values are the same for all levels of y. An example of this x is time which is the same for all subjects.

id

A numerical variable with 1, 2, ... indicating the subject.

Details

This is a special case of a balanced random intercepts model with a compound symmetric covariance matrix and one single covariate which is constant for all replicates. An example, is time, which is the same for all subjects. Maximum likelihood estimation has been performed. In this case the mathematics exist in a closed formula (Demidenko, 2013, pg. 67-69).

This is the generalistion of rint.regbx to matrices. Assume you have many observations, gene expressions over time for example, and you want to calculate the random effects or something else for each expression. Instead of using a "for" loop with rint.regbx function we have used amtrix operations to make it even faster.

Value

A list including:

info

A matrix with the random intercepts variance (between), the variance of the errors (within), the log-likelihood, the deviance (twice the log-likelihood) and the BIC. In the case of "rint.reg" it also includes the number of iterations required by the generalised least squares.

be

The estimated regression coefficients, which in the case of "rint.regbx" are simply two: the constant and the slope (time effect).

ranef

A matrix with random intercepts effects. Each row corresponds to a column in y. Instead of having a matrix with the same number of columns as y we return a transposed matrix.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Eugene Demidenko (2013). Mixed Models: Theory and Applications with R, 2nd Edition. New Jersey: Wiley & Sons (excellent book).

See Also

colvarcomps.mle, rint.regbx, rm.lines, varcomps.mom, rint.reg

Examples

y <- matrix( rnorm(100 * 50), ncol = 50)
id <- rep(1:20, each = 5)
x <- rep(1:10, 10)
a<- colrint.regbx(y, x, id)

Many regression based tests for single sample repeated measures

Description

Many regression based tests for single sample repeated measures.

Usage

rm.lines(y, x, logged = FALSE)
rm.anovas(y, x, logged = FALSE)

Arguments

y

A matrix with the data, where each column refers to a different sample of subjects. For example, the first column is the repeated measurements of a sample of subjects, the second column contains repeated measurements of a second sample of subjects and so on. Within each column, the measurements of each subjects are stacked one upon the other. Say for examples there are n subjects and each of them has been measured d times (in time or at different experimental conditions). We put these in a matrix with just one column. The first d rows are the measurements of subject 1, the next d rows are the measurements of subject 2 and so on.

x

A numerical vector with time (usually) or the the predictor variable. For example the temperature, or the pressure. See the details for more information. Its length is equal to the time points for example, i.e. it must not have the same length as the number of rows of y. For the "rm.lines" this is a continuous variable.

For the "rm.anovas" this is treated as a categorical variable, indicating say the type of experimental condition, but no difference between the points is important. Hence, for this function only, x can also be a facto variable.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

In order to see whether the repeated measurements are associated with a single covariate, e.g. time we perform many regressions and each time calculate the slope. For each subject, its regression slope with the covariate is calculated. In the end a t-test for the hypothesis that the average slopes is zero is performed. The regression slopes ignore that the measurements are not independent, but note that the slopes are independent, because they come from different subjects. This is a simple, summary statistics based approach found in Davis (2002), yet it can provide satisfactory results.

The second approach ("rm.anovas") found in Davis (2002) is the usual repeated measures ANOVA. In this case, suppose you have taken measurements on one or more variables from the same group of people. See the example below on how to put such data.

Value

A matrix with the test statistic (t-test) and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Charles S. Davis (2002). Statistical methods for the analysis of repeated measures. Springer-Verlag, New York.

See Also

rint.regbx, rint.reg, varcomps.mle

Examples

y <- c(74.5,81.5,83.6,68.6,73.1,79.4,
75.5,84.6,70.6,87.3,73.0,75.0,
68.9,71.6,55.9,61.9,60.5,61.8,
57.0,61.3,54.1,59.2,56.6,58.8,
78.3,84.9,64.0,62.2,60.1,78.7,
54.0,62.8,63.0,58.0,56.0,51.5,
72.5,68.3,67.8,71.5,65.0,67.7,
80.8,89.9,83.2,83.0,85.7,79.6)
y <- as.matrix(y)
### the first 6 measurements are from subject 1, measurments 7-12 are from subject 2,
## measurements 13-18 are from subject 3 and so on.
x <- c(-10, 25, 37, 50, 65, 80) ## all subjects were measured at the same time points
res<-rm.lines(y, x) ## Is linear trend between the measurements and the temperature?
res<-rm.anovas(y, x)  ## Tests whether the means of the individuals are the same
## the temperature is treated as categorical variable here.

## fake example
y <- matrnorm(10, 4)
## the y matrix contains 4 repeated measurements for each of the 10 persons.
x <- 1:4
## we stack the measurements of each subject, one under the other in a matrix form.
y1 <- matrix( t(y) )
res<-rm.anovas(y1, x)  ## perform the test
z <- matrix( rnorm(20 * 8), ncol = 2) ## same example, but with 2 sets of measurements.
res<-rm.anovas(z, x)

Many score based regressions

Description

Many score based GLM regressions.

Usage

score.glms(y, x, oiko = NULL, logged = FALSE) 
score.multinomregs(y, x, logged = FALSE) 
score.negbinregs(y, x, type = 1, logged = FALSE) 
score.weibregs(y, x, logged = FALSE) 
score.betaregs(y, x, logged = FALSE) 
score.gammaregs(y, x, logged = FALSE) 
score.expregs(y, x, logged = FALSE)
score.invgaussregs(y, x, logged = FALSE)
score.ztpregs(y, x, logged = FALSE)
score.geomregs(y, x, logged = FALSE)

Arguments

y

A vector with either discrete or binary data for the Poisson, geometric, or negative binomial and binary logistic regressions, respectively. A vector with discrete values or factor values for the multinomial regression. If the vector is binary and choose multinomial regression the function checks and transfers to the binary logistic regression.

For the Weibull, gamma, inverse Gaussian and exponential regressions they must be strictly positive data, lifetimes or durations for example. For the beta regression they must be numbers between 0 and 1. For the zero truncated Poisson regression (score.ztpregs) they must be integer valued data strictly greater than 0.

x

A matrix with data, the predictor variables.

oiko

This can be either "poisson" or "binomial". If you are not sure leave it NULL and the function will check internally.

type

This argument is for the negative binomial distribution. In the negative binomial you can choose which way your prefer. Type 1 is for smal sample sizes, whereas type 2 is for larger ones as is faster.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Details

Instead of maximising the log-likelihood via the Newton-Raphson algorithm in order to perform the hypothesis testing that βi=0\beta_i=0 we use the score test. This is dramatcially faster as no model needs to be fitted. The first derivative (score) of the log-likelihood is known and in closed form and under the null hypothesis the fitted values are all equal to the mean of the response variable y. The variance of the score is also known in closed form. The test is not the same as the likelihood ratio test. It is size correct nonetheless but it is a bit less efficient and less powerful. For big sample sizes though (5000 or more) the results are the same. We have seen via simulation studies is that it is size correct to large sample sizes, at elast a few thousands. You can try for yourselves and see that even with 500 the results are pretty close. The score test is pretty faster than the classical log-likelihood ratio test.

Value

A matrix with two columns, the test statistic and its associated p-value. For the Poisson and logistic regression the p-value is derived via the t distribution, whereas for the multinomial regressions via the χ2\chi^2 distribution.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Tsagris M., Alenazi A. and Fafalios S. (2020). Computationally efficient univariate filtering for massive data. Electronic Journal of Applied Statistical Analysis, 13(2):390-412.

Hosmer DW. JR, Lemeshow S. and Sturdivant R.X. (2013). Applied Logistic Regression. New Jersey ,Wiley, 3rd Edition.

Campbell M.J. (2001). Statistics at Square Two: Understand Modern Statistical Applications in Medicine, pg. 112. London, BMJ Books.

Draper N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

McCullagh Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

Agresti Alan (1996). An introduction to categorical data analysis. New York: Wiley.

Joseph M.H. (2011). Negative Binomial Regression. Cambridge University Press, 2nd edition.

See Also

univglms, logistic_only, poisson_only, regression

Examples

x <- matrnorm(500, 500)
y <- rbinom(500, 1, 0.6)   ## binary logistic regression
a2 <- score.glms(y, x)
y <- rweibull(500, 2, 3)   
a <- score.weibregs(y, x) 
mean(a[, 2] < 0.05) 
x <- NULL

Many Shapiro-Francia normality tests

Description

Many Shapiro-Francia normality tests.

Usage

sftests(x, logged = FALSE)
sftest(x, logged = FALSE)

Arguments

x

A matrix with the data, where the rows denote the observations and the columns are the variables. In the case of a single sample, then this must be a vector and "sftest" is to be used.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The Shapiro-Francia univariate normality test is performed for each column (variable) of the matrix x.

Value

A matrix with the squared correlation between the ordered values and the standard normal ordered statistics, the test statistic and the p-value of each test. If the "sftest" has been used, the output is a vector with these three elements.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Royston J. P. (1983). A simple method for evaluating the Shapiro-Francia W' test of non-normality. The Statistician, 32(3): 297-300.

Mbah A. K. & Paothong A. (2015). Shapiro-Francia test compared to other normality test using expected p-value. Journal of Statistical Computation and Simulation, 85(15): 3002-3016.

See Also

ttests, ttest, ftests

Examples

x <- matrnorm(200, 100)
sftests(x)
a <- sftests(x)
mean(a[, 3]<0.05) 
x <- rnorm(100)
res<-sftest(x)

Many simple circular or angular regressions

Description

Many regressions with one circular dependent variable and one Euclidean independent variable.

Usage

spml.regs(y, x, tol = 1e-07, logged = FALSE, maxiters = 100, parallel = FALSE)

Arguments

y

The dependent variable, it can be a numerical vector with data expressed in radians or it can be a matrix with two columns, the cosinus and the sinus of the circular data. The benefit of the matrix is that if the function is to be called multiple times with the same response, there is no need to transform the vector every time into a matrix.

x

A matrix with independent variable.

tol

The tolerance value to terminatate the Newton-Raphson algorithm.

logged

Do you want the logarithm of the p-value be returned? TRUE or FALSE.

maxiters

The maximum number of iterations to implement.

parallel

Do you want the calculations to take plac ein parallel? The default value if FALSE.

Details

The Newton-Raphson algorithm is fitted in these regression as described in Presnell et al. (1998). For each colum of x a circual regression model is fitted and the hypothesis testing of no association between y and this variable is performed.

Value

A matrix with two columns, the test statistics and their associated (log) p-values.

Author(s)

Michail Tsagris and Stefanos Fafalios

R implementation and documentation: Michail Tsagris <[email protected]> and Stefanos Fafalios <[email protected]>

References

Presnell Brett, Morrison Scott P. and Littell Ramon C. (1998). Projected multivariate linear models for directional data. Journal of the American Statistical Association, 93(443): 1068-1077.

See Also

spml.mle, iag.mle, acg.mle

Examples

x <- rnorm(100)
z <- cbind(3 + 2 * x, 1 -3 * x)
y <- cbind( rnorm(100,z[ ,1], 1), rnorm(100, z[ ,2], 1) )
y <- y / sqrt( rowsums(y^2) )
x <- matrnorm(100, 100)
a <- spml.regs(y, x)
x <- NULL

Many simple geometric regressions.

Description

Many simple geometric regressions.

Usage

geom.regs(y, x, tol = 1e-07, type = 1, logged = FALSE, parallel = FALSE, maxiters = 100)

Arguments

y

The dependent variable, count data.

x

A matrix with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

type

Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

parallel

Do you want this to be executed in parallel or not. The parallel takes place in C++, and the number of threads is defined by each system's availiable cores.

maxiters

The max number of iterations that can take place in each regression.

Details

Many simple geometric regressions are fitted.

Value

A matrix with the test statistic values, their relevant (logged) p-values and the BIC values.

Author(s)

Stefanos Fafalios

R implementation and documentation: Stefanos Fafalios <[email protected]>

See Also

poisson_only, prop.regs, score.geomregs

Examples

y <- rgeom(100, 0.6)
x <- matrix( rnorm(100 * 50), ncol = 50)
a <- geom.regs(y, x)
x <- NULL

Many simple linear mixed model regressions

Description

Many simple linear mixed model regressions with random intercepts only.

Usage

rint.regs(y, x, id, tol = 1e-08, logged = FALSE, parallel = FALSE, maxiters = 100)

Arguments

y

A numerical vector with the data. The subject values, the clustered data.

x

A numerical matrix with data ,the independent variables.

id

A numerical variable with 1, 2, ... indicating the subject. Unbalanced design is of course welcome.

tol

The tolerance value to terminate the Newton-Raphson algorithm. This is set to 10910^{-9} by default.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

parallel

Do you want this to be executed in parallel or not. The parallel takes place in C++, and the number of threads is defined by each system's availiable cores.

maxiters

The max number of iterations that can take place in each regression.

Details

Many linear mixed models with a single covariate are fitted. We use Newton-Raphson as described in Demidenko (2013). The test statistic is the usual F-test. This model allows for random intercepts only.

Value

A two-column matrix with the test statistics (Wald statistic) and the associated p-values (or their loggarithm).

Author(s)

Stefanos Fafalios.

R implementation and documentation: Stefanos Fafalios <[email protected]>.

References

Eugene Demidenko (2013). Mixed Models: Theory and Applications with R, 2nd Edition. New Jersey: Wiley & Sons (excellent book).

See Also

rint.reg, allbetas univglms, score.glms, logistic_only

Examples

## not a so good example
y <- rnorm(100)
id <- sample(1:10, 100, replace = TRUE)
x <- matrix( rnorm(100 * 100), ncol = 100)
a <- rint.regs(y, x, id)
x <- NULL

Simple linear regressions coefficients

Description

Simple linear regressions coefficients.

Usage

allbetas(y, x, pvalue = FALSE, logged = FALSE)

Arguments

y

A numerical vector with the response variable.

x

A matrix with the data, where rows denotes the observations and the columns contain the independent variables.

pvalue

If you want a hypothesis test that each slope (beta coefficient) is equal to zero set this equal to TRUE. It will also produce all the correlations between y and x.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Value

A matrix with the constant (alpha) and the slope (beta) for each simple linear regression. If the p-value is set to TRUE, the correlation of each y with the x is calculated along with the relevant test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

mvbetas, correls, univglms, colsums, colVars

Examples

x <- matrix( rnorm(100 * 50), ncol = 50 )
y <- rnorm(100)
r <- cor(y, x)  ## correlation of y with each of the xs
a <- allbetas(y, x)  ## the coefficients of each simple linear regression of y with x
x <- NULL

Many simple multinomial regressions.

Description

Many simple multinomial regressions.

Usage

multinom.regs(y, x, tol = 1e-08, logged = FALSE, parallel = FALSE, maxiters = 100)

Arguments

y

The dependent variable, either a numerical variable or a factor variable.

x

A matrix with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

parallel

Do you want this to be executed in parallel or not. The parallel takes place in C++, and the number of threads is defined by each system's availiable cores.

maxiters

The maximum number of iterations that can take place in each regression.

Details

Many simple multinomial regressions are fitted.

Value

A matrix with the test statistic values, their relevant (logged) p-values and the BIC values.

Author(s)

Stefanos Fafalios

R implementation and documentation: Stefanos Fafalios <[email protected]>

See Also

poisson_only, prop.regs, score.geomregs

Examples

y <- rbinom(100, 2, 0.5)
x <- matrnorm(100, 100)
a <- multinom.regs(y, x)
x <- NULL

Many simple regressions for positive valued data

Description

Many simple regressions for positive valued data.

Usage

normlog.regs(y, x, tol = 1e-08, logged = FALSE, parallel = FALSE, maxiters = 100)
gammaregs(y, x, tol = 1e-07, logged = FALSE, maxiters = 100)
invgauss.regs(y, x, tol = 1e-08, logged = FALSE, maxiters = 100)

Arguments

y

The dependent variable, a numerical variable with non negative numbers for the Gamma and inverse Gaussian regressions. For the Gaussian with a log-link zero values are allowed.

x

A matrix with the indendent variables.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

parallel

Do you want this to be executed in parallel or not. The parallel takes place in C++, therefore you do not have the option to set the number of cores.

maxiters

The maximum number of iterations that can take place in each regression.

Details

Many simple Gamma, inverse Gaussian or Gaussian regressions with a log-link are fitted.

Value

A matrix with the test statistic values and their relevant (logged) p-values.

Author(s)

Stefanos Fafalios and and Michail Tsagris

R implementation and documentation: Stefanos Fafalios <[email protected]> and Michail Tsagris <[email protected]>

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

Zakariya Yahya Algamal and Intisar Ibrahim Allyas (2017). Prediction of blood lead level in maternal and fetal using generalized linear model. International Journal of Advanced Statistics and Probability, 5(2): 65-69.

See Also

normlog.reg, score.glms, prop.regs, allbetas

Examples

y <- abs( rnorm(100) )
x <- matrnorm(100, 100)
a <- normlog.regs(y, x)
b <- glm(y ~ x[, 1], family = gaussian(log) )
anova(b, test= "F")
a[1, ]
a2 <- gammaregs(y, x)
a3 <- invgauss.regs(y, x)
x <- NULL

Many tests for the dispersion parameter in Poisson distribution

Description

Many tests for the dispersion parameter in Poisson distribution.

Usage

colpoisdisp.tests(y, alternative = "either", logged = FALSE)
colpois.tests(y, logged = FALSE)

Arguments

y

A numerical matrix with count data, 0, 1,...

alternative

Do you want to test specifically for either over or underspirsion ("either"), overdispersion ("over") or undersispersion ("under")?

logged

Set to TRUE if you want the logarithm of the p-value.

Value

A matrix with two columns, the test statistic and the (logged) p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Yang Zhao, James W. Hardin, and Cheryl L. Addy. (2009). A score test for overdispersion in Poisson regression based on the generalized Poisson-2 model. Journal of statistical planning and inference 139(4):1514-1521.

Dimitris Karlis and Evdokia Xekalaki (2000). A Simulation Comparison of Several Procedures for Testing the Poisson Assumption. Journal of the Royal Statistical Society. Series D (The Statistician), 49(3): 355-382.

Bohning, D., Dietz, E., Schaub, R., Schlattmann, P. and Lindsay, B. (1994) The distribution of the likelihood ratio for mixtures of densities from the one-parameter exponential family. Annals of the Institute of Statistical Mathematics, 46(): 373-388.

See Also

poisson.mle, negbin.mle, poisson.anova, poisson.anovas, poisson_only

Examples

y <- matrix(rnbinom(100* 50, 10, 0.6), ncol = 50)
a1 <- colpoisdisp.tests(y, "over")
b1 <- colpois.tests(y)

y <- matrix(rpois(100* 50, 10), ncol = 50)
a2 <- colpoisdisp.tests(y, "either")
b2 <- colpois.tests(y)
y <- NULL

Many two-way ANOVAs

Description

Many two-way ANOVAs.

Usage

twoway.anovas(y, x1, x2, interact = FALSE, logged = FALSE)

Arguments

y

A matrix with the data, where the rows denote the observations (and the two groups) and the columns are the variables.

x1

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Alternatively it can be a factor variable. This is the one factor.

x2

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Alternatively it can be a factor variable. This is the other factor.

interact

A boolean variable specifying whether you want to test for interaction.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The classical two-way ANOVA design is performed. Note that the design must be balanced. For every combination of values of the two factors, x1 and x2 the same number of observations must exist. If that's not the case, regression models must be used.

Value

A matrix with the test statistic and the p-value of each test.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

D.C. Montgomery (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons.

See Also

ancovas, ftests, ttests

Examples

y <- as.matrix( rnorm(125) )
x1 <- rep(1:5, 25)
x2 <- rep(1:5, each = 25)
x1 <- factor(x1)
x2 <- factor(x2)  
res<-anova( lm(y ~ x1 + x2) )
res<-twoway.anovas(y, x1, x2)
res<-anova( lm(y ~ x1*x2) )
res<-twoway.anovas(y, x1, x2, interact = TRUE) 
y <- matrnorm(125, 100)
a1 <- twoway.anovas(y, x1, x2)
a2 <- twoway.anovas(y, x1, x2, interact = TRUE)
y <- NULL

Many univariate generalised linear regressions

Description

It performs very many univariate generalised linear regressions.

Usage

univglms(y, x, oiko = NULL, logged = FALSE)

univglms2(y, x, oiko = NULL, logged = FALSE)

Arguments

y

The dependent variable. It can be a factor or a numerical variable with two values only (binary logistic regression), a discrete valued vector (count data) corresponding to a poisson regression or a numerical vector with continuous values (normal regression).

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. For the "univglms" only continuous variables are allowed. You are advised to standardise the data before hand to avoid numerical overflow or similar issues. If you see NaN in the outcome, this might be the case. For the "univglms2" categorical variables are allowed and hence this accepts data.frames. In this case, the categorical variables must be given as factor variables, otherwise you might get wrong results.

oiko

This can be either "normal", "poisson", "quasipoisson" or "binomial". If you are not sure leave it NULL and the function will check internally. However, you might have discrete data (e.g. years of age) and want to perform many simple linear regressions. In this case you should specify the family.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Details

If you specify no family of distributions the function internally checkes the type of your data and decides on the type of regression to perform. The function is written in C++ and this is why it is very fast. It can accept thousands of predictor variables. It is usefull for univariate screening. We provide no p-value correction (such as fdr or q-values); this is up to the user.

Value

A matrix with the test statistic and the p-value for each predictor variable.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

logistic_only, poisson_only, allbetas, correls, regression

Examples

x <- matrnorm(100, 50)
y <- rbinom(100, 1, 0.6)   ## binary logistic regression
a1 <- univglms(y, x) 
a2 <- glm(y ~ x[, 1], binomial)$deviance
a2 <- glm(y ~ 1, binomial)$null.dev - a2
x <- NULL

Many univariate simple linear regressions

Description

It performs very many univariate simple linear regressions with or without categorical variables.

Usage

regression(x, y, poia = NULL, logged = FALSE)

Arguments

x

A data.frame or a matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. A data frame is expected if you have categorical predictor variables. If you only have continuous predictor variables you should the function allbetas instead as it is faster.

y

The dependent variable; a numerical vector.

poia

If the "x" is a data.frame and you know the indices of the columns which are categorical variables supply it here.

logged

Do you want the logarithm of the p-values be returned? The default value is FALSE.

Details

Some parts of the function will be transferred in C++. It can accept thousands of predictor variables. It is usefull for univariate screening. We provide no p-value correction (such as fdr or q-values); this is up to the user.

Value

A matrix with two columns, the test statistic value and its corresponding (logged) p-value.

Author(s)

Manos Papadakis <[email protected]>

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

univglms, allbetas, correls, univglms, mvbetas

Examples

y <- rnorm(150)   
a <- regression(iris, y)
a
summary(lm(y ~ iris[, 5]) )  ## check the F-test

Many univariate simple binary logistic regressions

Description

It performs very many univariate simple binary logistic regressions.

Usage

logistic_only(x, y, tol = 1e-09, b_values = FALSE)
poisson_only(x, y, tol = 1e-09, b_values = FALSE)

Arguments

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. Currently only continuous variables are allowed.

y

The dependent variable; a numerical vector with two values (0 and 1) for the logistic regressions and a vector with many discrete values (count data) for the Poisson regressions.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

b_values

Do you want the values of the coefficients returned? If yes, set this to TRUE.

Details

The function is written in C++ and this is why it is very fast. It can accept thousands of predictor variables. It is usefull for univariate screening. We provide no p-value correction (such as fdr or q-values); this is up to the user.

Value

A vector with the deviance of each simple binayr logistic regression model for each predictor variable.

Author(s)

Manos Papadakis <[email protected]>

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

univglms, score.glms, prop.regs, quasi.poisson_only, allbetas, correls, regression

Examples

## 300 variables, hence 300 univariate regressions are to be fitted
x <- matrix( rnorm(100 * 300), ncol = 300 )

## 100 observations in total
y <- rbinom(100, 1, 0.6)   ## binary logistic regression
a1 <- logistic_only(x, y)
 
a2 <- glm(y ~ x[, 1], binomial)$deviance 
a2 <- as.vector(a2)

y <- rpois(100, 10)
a1 <- poisson_only(x, y) 

a1 <- x <- NULL

Many univariate simple poisson regressions

Description

It performs very many univariate simple poisson regressions.

Usage

quasi.poisson_only(x, y, tol = 1e-09, maxiters = 100)

Arguments

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. Currently only continuous variables are allowed.

y

The dependent variable; a numerical vector with many discrete values (count data).

maxiters

The maximum number of iterations after which the Newton-Raphson algorithm is terminated.

tol

The tolerance value to terminate the Newton-Raphson algorithm.

Details

The function is written in C++ and this is why it is very fast. It can accept thousands of predictor variables. It is usefull for univariate screening. We provide no p-value correction (such as fdr or q-values); this is up to the user.

Value

A matrix with the deviance and the estimated phi parameter (dispersion parameter) of each simple poisson regression model for each predictor variable.

Author(s)

Manos Papadakis <[email protected]> and Stefanos Fafalios <[email protected]>

R implementation and documentation: Michail Tsagris <[email protected]>, Manos Papadakis <[email protected]> and Stefanos Fafalios <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

poisson_only univglms, logistic_only, allbetas, regression

Examples

## 200 variables, hence 200 univariate regressions are to be fitted
x <- matrix( rnorm(100 * 200), ncol = 200 )
y <- rpois(100, 10)
poisson_only(x, y)
b1 <- poisson_only(x, y) 
b2 <- quasi.poisson_only(x, y) 

b1<-b2<-x<-y<-NULL

Many Welch's F-tests

Description

Many Welch's F-tests.

Usage

colanovas(y, x, logged = FALSE)

Arguments

y

A numerical vector with the dependent variable.

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. This must be a matrix with the categorical variables as numbers, starting from 1. Welch's F-test is performed for each variable.

logged

A boolean variable; it will return the logarithm of the pvalue if set to TRUE.

Details

For each categorical variable in the x matrix Welch's F test is performed. This is the opposie of ftests, where there are many dependent variables and one categorical variable.

Value

A matrix with the test statistic and the p-value for each predictor variable.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Draper, N.R. and Smith H. (1988). Applied regression analysis. New York, Wiley, 3rd edition.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

regression, ftests, allbetas, correls

Examples

y <-  rnorm(100)
x <- matrix( rbinom(100 * 50, 2, 0.5) + 1 , ncol = 50)  
a <- colanovas(y, x)
x <- NULL

Matrix multiplication, Cross and Tcross product.

Description

Matrix multiplication, Cross and Tcross product.

Usage

mat.mult(x, y)
Crossprod(x,y)
Tcrossprod(x,y)

Arguments

x

A numerical matrix.

y

A numerical matrix.

Details

The functions performs matrix multiplication, croos product and transpose cross product. There are faster(!) than R's function for large matrices. Depending on the computer, maybe higher dimensions are required for the function to make a difference. The function runs in parallel in C++.

Value

A matrix, the result of the matrix multiplication.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>

See Also

transpose, colsums

Examples

x <- matrnorm(100, 100)
y <- matrnorm(100, 100)
a <- x 
b <- mat.mult(x, y)
b <- Crossprod(x, y)
b <- Tcrossprod(x, y)
x <- NULL
y <- NULL
b <- NULL

Matrix with all pairs of t-tests

Description

Matrix with all pairs of t-tests.

Usage

allttests(x, y = NULL, ina, logged = FALSE) 
ttests.pairs(x, logged = FALSE)

Arguments

x

A numerical matrix with the data.

y

For the case of "all.tests", if you have the second group or sample provide it here, otherwise leave it NULL. For the case of "ttests.pairs" this is not required.

ina

If you have the data in one matric then provide this indicator variable separating the samples. This numerical vector must contain 1s and 2s only as values. For the case of "ttests.pairs" this is not required.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The function does all the pairwise t-tests assuming unequal variances (Welch's t-test). The "all.ttests" does all the pairs formed by "cutting" the matrices x and y in two and everything between them. The "ttests.pairs" accepts a matrix x and does all the pairs of t-tests. This is similar to the correlation matrix style.

Value

A list including:

stat

A matrix with t-test statistic for each pair of variables.

pvalue

A matrix with the corresponding p-values.

dof

A matrix with the relevant degrees of freedom.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

ttests, ftests, ttest, g2Test_univariate

Examples

x <- as.matrix( iris[1:100, 1:4] )
ina <- as.numeric(iris[1:100, 5])
a <- allttests(x, ina = ina)
b <- ttests.pairs(x)  ## less tests

Matrix with G-square tests of indepdence

Description

Matrix with G-square tests of indepdence with and without permutations.

Usage

g2Test_univariate(data, dc)
g2Test_univariate_perm(data, dc, nperm) 
chi2Test_univariate(data, dc)

Arguments

data

A numerical matrix with the data. The minimum must be 0, otherwise the function can crash or will produce wrong results. The data must be consecutive numbers.

dc

A numerical value equal to the number of variables (or columns of the data matrix) indicating the number of distinct, unique values (or levels) of each variable. Make sure you give the correct numbers here, otherwise the degrees of freedom will be wrong.

nperm

The number of permutations. The permutations test is slower than without permutations and should be used with small sample sizes or when the contigency tables have zeros. When there are few variables, R's "chisq.test" function is faster, but as the number of variables increase the time difference with R's procedure becomes larger and larger.

Details

The function does all the pairwise G2G^2 test of independence and gives the position inside the matrix. The user must build the associations matrix now, similarly to the correlation matrix. See the examples of how to do that. The p-value is not returned, we live this to the user. See the examples of how to obtain it.

Value

A list including:

statistic

The G2G^2 or chi2chi^2 test statistic for each pair of variables.

pvalue

This is returned when you have selected the permutation based G2G^2 test.

x

The row or variable of the data.

y

The column or variable of the data.

df

The degrees of freedom of each test.

Author(s)

Giorgos Borboudakis. The permutation version used a C++ code by John Burkardt.

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Tsagris M. (2017). Conditional independence test for categorical data using Poisson log-linear model. Journal of Data Science, 15(2):347-356.

Tsamardinos, I., & Borboudakis, G. (2010). Permutation testing improves Bayesian network learning. In Joint European Conference on Machine Learning and Knowledge Discovery in Databases (pp. 322-337). Springer Berlin Heidelberg

See Also

g2Test, g2Test_perm, correls, univglms

Examples

nvalues <- 3
nvars <- 10
nsamples <- 2000
data <- matrix( sample( 0:(nvalues - 1), nvars * nsamples, replace = TRUE ), nsamples, nvars )
dc <- rep(nvalues, nvars)
g2Test_univariate(data = data, dc = dc)
a <- g2Test_univariate(data = data, dc = dc)
pval <- pchisq(a$statistic, a$df, lower.tail = FALSE)

g <- matrix(0, nvars, nvars)
g[ cbind(a$x, a$y) ] <- a$statistic
g <- g + t(g)
diag(g) <- 0
## g ## matrix of G^2 test statistics

g<-a<-dc<-data<-NULL

Minima and maxima of two vectors/matrices and Column-row wise minima and maxima of two matrices

Description

Minima and maxima of two vectors/matrices and Column-row wise minima and maxima of two matrices.

Usage

colPmax(x, y)
colPmin(x, y)
Pmax(x, y,na.rm = FALSE)
Pmin(x, y,na.rm = FALSE)
Pmin_Pmax(x, y,na.rm = FALSE)

Arguments

x

A numerical vector or matrix with numbers.

y

A numerical vector with numbers.

na.rm

TRUE or FAlSE for remove NAs if exists.

Details

The parallel minima or maxima are returned. This are the same as the base functions pmax and pmin.

Value

A numerical vector/matrix with numbers, whose length is equal to the length of the initital matrices containing the maximum or minimum between each pair.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Sort, colMins, colMaxs, colMedians

Examples

x <- matrix(rnorm(100),10,10)
y <- matrix(rnorm(100),10,10)
res<-colPmax(x, y)
res<-colPmin(x, y)
x<-y<-NULL

Minimum and maximum of a vector

Description

Minimum and maximum of a vector.

Usage

min_max(x,index=FALSE, percent = FALSE)

Arguments

x

A numerical vector with data. NAs are handled naturally.

index

A boolean value for the indices of the minimum and the maximum value.

percent

A boolean value for the percent of the positive and negative numbers.

Value

A vector with the relevant values, min and max.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, rowMaxs, nth, colrange, colMedians,colSort, rowSort

Examples

x <- rnorm(100 * 500)
s1 <- min_max(x) 
s2 <- c(min(x), max(x))

Minimum and maximum frequencies of a vector

Description

Minimum and maximum frequencies of a vector.

Usage

freq.min(x,na.rm = FALSE)
freq.max(x,na.rm = FALSE)

Arguments

x

A numerical/integer vector with data but without NAs.

na.rm

TRUE or FAlSE for remove NAs if exists.

Details

Those functions are the same with max(table(x) or min(table(x)) but with one exception. freq.min and freq.max will return also which value has the minimum/maximum frequency. More Efficient than max(table(x) or min(table(x)).

Value

A vector with 2 values, the value with minimum/maximum frequency and the frequency.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]> and Marios Dimitriadis <[email protected]>.

See Also

rowMins, rowMaxs, nth, colrange, colMedians,colSort, rowSort

Examples

x <- rnorm(100)
f1 <- freq.min(x) 
f2 <- freq.max(x) 
# f1r <- min(table(x))
# f2r <- max(table(x))
# f1[2]==f1r ## the frequencies are the same
# f2[2]==f2r ## the frequencies are the same

MLE for multivariate discrete data

Description

MLE for multivariate discrete data.

Usage

multinom.mle(x)
dirimultinom.mle(x, tol = 1e-07) 
colpoisson.mle(x)
colgeom.mle(x, type = 1)

Arguments

x

A matrix with discrete valued non negative data.

tol

the tolerance level to terminate the Newton-Raphson algorithm for the Dirichlet multinomial distribution.

type

This is for the geometric distribution only. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

Details

For the Poisson and geometric distributions we simply fit independent Poisson and geometric distributions respectively.

Value

A list including:

loglik

A vector with the value of the maximised log-likelihood.

param

A vector of the parameters.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Johnson Norman L., Kotz Samuel and Balakrishnan (1997). Discrete Multivariate Distributions. Wiley

Minka Thomas (2012). Estimating a Dirichlet distribution. Technical report.

See Also

poisson.mle, zip.mle, ztp.mle, negbin.mle, poisson.nb

Examples

x <- t( rmultinom(1000, 20, c(0.4, 0.5, 0.1) ) )
res<-multinom.mle(x)
res<-colpoisson.mle(x)
x <- NULL

MLE of (hyper-)spherical distributions

Description

MLE of (hyper-)spherical distributions.

Usage

vmf.mle(x, tol = 1e-07)
multivmf.mle(x, ina, tol = 1e-07, ell = FALSE)
acg.mle(x, tol = 1e-07)
iag.mle(x, tol = 1e-07)

Arguments

x

A matrix with directional data, i.e. unit vectors.

ina

A numerical vector with discrete numbers starting from 1, i.e. 1, 2, 3, 4,... or a factor variable. Each number denotes a sample or group. If you supply a continuous valued vector the function will obviously provide wrong results.

ell

This is for the multivmf.mle only. Do you want the log-likelihood returned? The default value is TRUE.

tol

The tolerance value at which to terminate the iterations.

Details

For the von Mises-Fisher, the normalised mean is the mean direction. For the concentration parameter, a Newton-Raphson is implemented. For the angular central Gaussian distribution there is a constraint on the estimated covariance matrix; its trace is equal to the number of variables. An iterative algorithm takes place and convergence is guaranteed. Newton-Raphson for the projected normal distribution, on the sphere, is implemented as well. Finally, the von Mises-Fisher distribution for groups of data is also implemented.

Value

For the von Mises-Fisher a list including:

loglik

The maximum log-likelihood value.

mu

The mean direction.

kappa

The concentration parameter.

For the multi von Mises-Fisher a list including:

loglik

A vector with the maximum log-likelihood values if ell is set to TRUE. Otherwise NULL is returned.

mi

A matrix with the group mean directions.

ki

A vector with the group concentration parameters.

For the angular central Gaussian a list including:

iter

The number if iterations required by the algorithm to converge to the solution.

cova

The estimated covariance matrix.

For the spherical projected normal a list including:

iters

The number of iteration required by the Newton-Raphson.

mesi

A matrix with two rows. The first row is the mean direction and the second is the mean vector. The first comes from the second by normalising to have unit length.

param

A vector with the elements, the norm of mean vector, the log-likelihood and the log-likelihood of the spherical uniform distribution. The third value helps in case you want to do a log-likleihood ratio test for uniformity.

Author(s)

Michail Tsagris R implementation and documentation: Michail Tsagris <[email protected]>

References

Mardia, K. V. and Jupp, P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.

Sra, S. (2012). A short note on parameter approximation for von Mises-Fisher distributions: and a fast implementation of Is(x). Computational Statistics, 27(1): 177–190.

Tyler D. E. (1987). Statistical analysis for the angular central Gaussian distribution on the sphere. Biometrika 74(3): 579-589.

Paine P.J., Preston S.P., Tsagris M and Wood A.T.A. (2017). An Elliptically Symmetric Angular Gaussian Distribution. Statistics and Computing (To appear).

See Also

racg, vm.mle, rvmf

Examples

m <- c(0, 0, 0, 0)
s <- cov(iris[, 1:4])
x <- racg(100, s)
mod <- acg.mle(x)
mod
res<-cov2cor(mod$cova)  ## estimated covariance matrix turned into a correlation matrix
res<-cov2cor(s)  ## true covariance matrix turned into a correlation matrix
res<-vmf.mle(x)
x <- rbind( rvmf(100,rnorm(4), 10), rvmf(100,rnorm(4), 20) )
a <- multivmf.mle(x, rep(1:2, each = 100) )

MLE of continuous univariate distributions defined on the positive line

Description

MLE of continuous univariate distributions defined on the positive line.

Usage

gammamle(x, tol = 1e-09) 
chisq.mle(x, tol = 1e-09)
weibull.mle(x, tol = 1e-09, maxiters = 100)
lomax.mle(x, tol = 1e-09)
foldnorm.mle(x, tol = 1e-09)
betaprime.mle(x, tol = 1e-09)
logcauchy.mle(x, tol = 1e-09)
loglogistic.mle(x, tol = 1e-09)
halfnorm.mle(x)
invgauss.mle(x)
lognorm.mle(x)
pareto.mle(x)
expmle(x)
exp2.mle(x)
maxboltz.mle(x)
rayleigh.mle(x)
normlog.mle(x)
lindley.mle(x)

Arguments

x

A vector with positive valued data (zeros are not allowed).

tol

The tolerance level up to which the maximisation stops; set to 1e-09 by default.

maxiters

The maximum number of iterations the Newton-Raphson will perform.

Details

Instead of maximising the log-likelihood via a numerical optimiser we have used a Newton-Raphson algorithm which is faster. See wikipedia for the equations to be solved. For the t distribution we need the degrees of freedom and estimate the location and scatter parameters. If you want to to fit an inverse gamma distribution simply do "gamma.mle(1/x)". The log-likelihood and the parameters are for the inverse gamma.

The "normlog.mle" is simply the normal distribution where all values are positive. Note, this is not log-normal. It is the normal with a log link. Similarly to the inverse gaussian distribution where the mean is an exponentiated. This comes from the GLM theory.

Value

Usually a list with three elements, but this is not for all cases.

iters

The number of iterations required for the Newton-Raphson to converge.

loglik

The value of the maximised log-likelihood.

param

The vector of the parameters.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Kalimuthu Krishnamoorthy, Meesook Lee and Wang Xiao (2015). Likelihood ratio tests for comparing several gamma distributions. Environmetrics, 26(8):571-583.

N.L. Johnson, S. Kotz and N. Balakrishnan (1994). Continuous Univariate Distributions, Volume 1 (2nd Edition).

N.L. Johnson, S. Kotz a nd N. Balakrishnan (1970). Distributions in statistics: continuous univariate distributions, Volume 2.

Tsagris M., Beneki C. and Hassani H. (2014). On the folded normal distribution. Mathematics, 2(1):12-28.

Sharma V. K., Singh S. K., Singh U. and Agiwal V. (2015). The inverse Lindley distribution: a stress-strength reliability model with application to head and neck cancer data. Journal of Industrial and Production Engineering, 32(3): 162-173.

You can also check the relevant wikipedia pages for these distributions.

See Also

zip.mle, normal.mle, beta.mle

Examples

x <- rgamma(100, 3, 4)
for (i in 1:20) gammamle(x)
## for (i in 1:20) fitdistr(x,"gamma")
#a <- glm(x ~ 1, gaussian(log) )
res<-normlog.mle(x)

MLE of continuous univariate distributions defined on the real line

Description

MLE of continuous univariate distributions defined on the real line.

Usage

normal.mle(x) 
gumbel.mle(x, tol = 1e-09)
cauchy.mle(x, tol = 1e-09)
logistic.mle(x, tol = 1e-07)
ct.mle(x, tol = 1e-09)
tmle(x, v = 5, tol = 1e-08)
wigner.mle(x, tol = 1e-09)
laplace.mle(x)

Arguments

x

A numerical vector with data.

v

The degrees of freedom of the t distribution.

tol

The tolerance level up to which the maximisation stops set to 1e-09 by default.

Details

Instead of maximising the log-likelihood via a numerical optimiser we have used a Newton-Raphson algorithm which is faster. See wikipedia for the equation to be solved. For the t distribution we need the degrees of freedom and estimate the location and scatter parameters.

The Cauchy is the t distribution with 1 degree of freedom. If you want to fit such a distribution used the cauchy.mle and not the t.mle with 1 degree of freedom as it's faster. The Laplace distribution is also called double exponential distribution.

The wigner.mle refers to the wigner semicircle distribution.

Value

Usually a list with three elements, but this is not for all cases.

iters

The number of iterations required for the Newton-Raphson to converge.

loglik

The value of the maximised log-likelihood.

param

The vector of the parameters.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Johnson, Norman L. Kemp, Adrianne W. Kotz, Samuel (2005). Univariate Discrete Distributions (third edition). Hoboken, NJ: Wiley-Interscience.

https://en.wikipedia.org/wiki/Wigner_semicircle_distribution

See Also

zip.mle, gammamle, vm.mle

Examples

x <- rt(1000,10)
a <- ct.mle(x)
res<-tmle(x, v = a$nu)
res<-cauchy.mle(x)
res<-normal.mle(x)
res<-logistic.mle(x)
res<-gumbel.mle(x)

MLE of count data

Description

MLE of count data.

Usage

zip.mle(x, tol = 1e-09)
ztp.mle(x, tol = 1e-09)
negbin.mle(x, type = 1, tol = 1e-09) 
binom.mle(x, N = NULL, tol = 1e-07)
borel.mle(x)
geom.mle(x, type = 1)
logseries.mle(x, tol = 1e-09)
poisson.mle(x)
betageom.mle(x, tol = 1e-07)
betabinom.mle(x, N, tol = 1e-07)

Arguments

x

A vector with discrete valued data.

type

This argument is for the negative binomial and the geometric distribution. In the negative binomial you can choose which way your prefer. Type 1 is for smal sample sizes, whereas type 2 is for larger ones as is faster. For the geometric it is related to its two forms. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

N

This is for the binomial distribution only, specifying the total number of successes. If NULL, it is sestimated by the data. It can also be a vector of successes.

tol

The tolerance level up to which the maximisation stops set to 1e-09 by default.

Details

Instead of maximising the log-likelihood via a numerical optimiser we used a Newton-Raphson algorithm which is faster.

See wikipedia for the equation to be solved in the case of the zero inflated distribution. https://en.wikipedia.org/wiki/Zero-inflated_model. In order to avoid negative values we have used link functions, log for the lambdalambda and logit for the π\pi as suggested by Lambert (1992). As for the zero truncated Poisson see https://en.wikipedia.org/wiki/Zero-truncated_Poisson_distribution.

zip.mle is for the zero inflated Poisson, whereas ztp.mle is for the zero truncated Poisson distribution.

Value

The following list is not inclusive of all cases. Different functions have different names. In general a list including:

mess

This is for the negbin.mle only. If there is no reason to use the negative binomial distribution a message will appear, otherwise this is NULL.

iters

The number of iterations required for the Newton-Raphson to converge.

loglik

The value of the maximised log-likelihood.

prob

The probability parameter of the distribution. In some distributions this argument might have a different name. For example, param in the zero inflated Poisson.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Lambert Diane (1992). Zero-Inflated Poisson Regression, with an Application to Defects in Manufacturing. Technometrics. 34 (1): 1-14

Johnson Norman L., Kotz Samuel and Kemp Adrienne W. (1992). Univariate Discrete Distributions (2nd ed.). Wiley

See Also

poisson_only, colrange

Examples

x <- rpois(100, 2)
res<-zip.mle(x)
res<-poisson.mle(x)
## small difference in the two log-likelihoods as expected.

x <- rpois(100, 10)
x[x == 0 ] <- 1
res<-ztp.mle(x)
res<-poisson.mle(x)
## significant difference in the two log-likelihoods. 

x <- rnbinom(100, 10, 0.6)
res<-poisson.mle(x)
res<-negbin.mle(x)

MLE of distributions defined in the (0, 1) interval

Description

MLE of distributions defined in the (0, 1) interval.

Usage

beta.mle(x, tol = 1e-09)
ibeta.mle(x, tol = 1e-09)
logitnorm.mle(x)
hsecant01.mle(x, tol = 1e-09)

Arguments

x

A numerical vector with proportions, i.e. numbers in (0, 1) (zeros and ones are not allowed).

tol

The tolerance level up to which the maximisation stops.

Details

Maximum likelihood estimation of the parameters of the beta distribution is performed via Newton-Raphson. The distributions and hence the functions does not accept zeros. "logitnorm.mle" fits the logistic normal, hence no nwewton-Raphson is required and the "hypersecant01.mle" uses the golden ratio search as is it faster than the Newton-Raphson (less calculations)

Value

A list including:

iters

The number of iterations required by the Newton-Raphson.

loglik

The value of the log-likelihood.

param

The estimated parameters. In the case of "hypersecant01.mle" this is called "theta" as there is only one parameter.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

See Also

diri.nr2,

Examples

x <- rbeta(1000, 1, 4)
for(i in 1:1000) beta.mle(x)
res<-beta.mle(x)
res<-ibeta.mle(x)

x <- runif(1000)
res<-hsecant01.mle(x)
res<-logitnorm.mle(x)
res<-ibeta.mle(x)

x <- rbeta(1000, 2, 5)
x[sample(1:1000, 50)] <- 0
res<-ibeta.mle(x)

MLE of some circular distributions

Description

MLE of some circular distributions.

Usage

vm.mle(x, tol = 1e-09)
spml.mle(x, tol = 1e-09, maxiters = 100)
wrapcauchy.mle(x, tol = 1e-09)

Arguments

x

A numerical vector with the circular data. They must be expressed in radians. For the "spml.mle" this can also be a matrix with two columns, the cosinus and the sinus of the circular data.

tol

The tolerance level to stop the iterative process of finding the MLEs.

maxiters

The maximum number of iterations to implement.

Details

The parameters of the von Mises, the bivariate angular Gaussian and wrapped Cauchy distributions are estimated. For the Wrapped Cauchy, the iterative procedure described by Kent and Tyler (1988) is used. As for the von Mises distribution, we use a Newton-Raphson to estimate the concentration parameter. The angular Gaussian is described, in the regression setting in Presnell et al. (1998).

Value

A list including:

iters

The iterations required until convergence. This is returned in the wrapped Cauchy distribution only.

loglik

The value of the maximised log-likelihood.

param

A vector consisting of the estimates of the two parameters, the mean direction for both distributions and the concentration parameter kappa and the rho for the von Mises and wrapped Cauchy respectively.

gamma

The norm of the mean vector of the angualr Gaussian distribution.

mu

The mean vector of the angular Gaussian distribution.

Author(s)

Michail Tsagris and Stefanos Fafalios

R implementation and documentation: Michail Tsagris <[email protected]> and Stefanos Fafalios <[email protected]>

References

Mardia K. V. and Jupp P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.

Sra S. (2012). A short note on parameter approximation for von Mises-Fisher distributions: and a fast implementation of Is(x). Computational Statistics, 27(1): 177-190.

Presnell Brett, Morrison Scott P. and Littell Ramon C. (1998). Projected multivariate linear models for directional data. Journal of the American Statistical Association, 93(443): 1068-1077.

Kent J. and Tyler D. (1988). Maximum likelihood estimation for the wrapped Cauchy distribution. Journal of Applied Statistics, 15(2): 247–254.

See Also

vmf.mle, rvonmises, rvmf

Examples

y <- rcauchy(100, 3, 1)
x <- y 
res<-vm.mle(x)
res<-spml.mle(x)
res<-wrapcauchy.mle(x)
x <- NULL

MLE of the inverted Dirichlet distribution

Description

MLE of the inverted Dirichlet distribution.

Usage

invdir.mle(x, tol = 1e-07)

Arguments

x

A matrix with strictly positive data (no zeros are allowed).

tol

The tolerance level up to which the maximisation stops.

Details

Maximum likelihood estimation of the parameters of the inverted is performed via Newton-Raphson. We took the initial values suggested by Bdiri T. and Bouguila N. (2012) and modified them a bit.

Value

A list including:

iters

The number of iterations required by the Newton Raphson.

loglik

The value of the log-likelihood.

param

The estimated parameters.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Bdiri T. and Bouguila N. (2012). Positive vectors clustering using inverted Dirichlet finite mixture models. Expert Systems with Applications, 39(2): 1869-1882.

See Also

diri.nr2, multinom.mle

Examples

x <- as.matrix(iris[, 1:4])
for(i in 1:10) invdir.mle(x)
res<-invdir.mle(x)

MLE of the multivariate (log-) normal distribution

Description

MLE of the multivariate (log-) normal distribution.

Usage

mvnorm.mle(x)
mvlnorm.mle(x)

Arguments

x

A matrix with numerical data.

Details

The mean vector, covariance matrix and the value of the log-likelihood of the multivariate normal or log-normal distribution is calculated. For the log-normal distribution we also provide the expected value and the covariance matrix.

Value

A list including:

loglik

The log-likelihood multivariate distribution.

mu

The mean vector.

sigma

The covariance matrix.

m

The expected mean vector of the multivariate log-normal distribution.

s

The expected covariance matrix of the multivariate log-normal distribution.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Kotz, S., Balakrishnan, N., & Johnson, N. L. (2004). Continuous multivariate distributions, Volume 1: Models and applications (Vol. 1). John wiley & sons.

http://isi.cbs.nl/iamamember/CD2/pdf/329.PDF

https://en.wikipedia.org/wiki/Log-normal_distribution#Multivariate_log-normal

See Also

multinom.mle, dmvnorm, gaussian.nb

Examples

x <- matrnorm(100, 4)
res<-mvnorm.mle(x)
x <- NULL

MLE of the multivariate t distribution

Description

MLE of the multivariate t distribution.

Usage

mvt.mle(x, v = 5, tol = 1e-07)

Arguments

x

A matrix with numerical data.

v

The degrees of freedom. Must be a positive number, greater than zero.

tol

The tolerance value to terminate the EM algorithm.

Details

The location vector, scatter matrix and the value of the log-likelihood is calculated.

Value

A list including:

iters

The number of iterations required for the EM algorihm to converge.

loglik

The value of the maximised log-likelihood.

location

The location vector.

scatter

The scatter matrix.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Nadarajah S. and Kotz S. (2008). Estimation methods for the multivariate t distribution. Acta Applicandae Mathematicae, 102(1):99-118.

See Also

mvnorm.mle, dmvnorm, gaussian.nb

Examples

x <- matrnorm(100, 4)
res<-mvnorm.mle(x)
res<-mvt.mle(x, v = 5)
res<-mvt.mle(x, v = 100)

MLE of the ordinal model without covariates

Description

MLE of the ordinal model without covariates.

Usage

ordinal.mle(y, link = "logit")

Arguments

y

A numerical vector with values 1, 2, 3,..., not zeros, or an ordered factor.

link

This can either be "logit" or "probit". It is the link function to be used.

Details

Maximum likelihood of the ordinal model (proportional odds) is implemented. See for example the "polr" command in R or the examples.

Value

A list including:

loglik

The log-likelihood of the model.

a

The intercepts (threshold coefficients) of the model.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Agresti, A. (2002) Categorical Data. Second edition. Wiley.

See Also

beta.mle, diri.nr2

Examples

y <- factor( rbinom(100,3,0.5), ordered = TRUE )
res<-ordinal.mle(y)
res<-ordinal.mle(y, link = "probit")

MLE of the tobit model

Description

MLE of the tobit model.

Usage

tobit.mle(y, tol = 1e-09)

Arguments

y

A vector with positive valued data and zero values. If there are no zero values, a simple normal model is fitted in the end.

tol

The tolerance level up to which the maximisation stops; set to 1e-09 by default.

Details

The tobin model is useful for (univariate) positive data with left censoring at zero. There is the assumption of a latent variable. Tthe values of that variable which are positive concide with the observed values. If some values are negative, they are left censored and the observed values are zero. Instead of maximising the log-likelihood via a numerical optimiser we have used a Newton-Raphson algorithm which is faster.

Value

A list with three elements including

iters

The number of iterations required for the Newton-Raphson to converge.

loglik

The value of the maximised log-likelihood.

param

The vector of the parameters.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Tobin James (1958). Estimation of relationships for limited dependent variables. Econometrica. 26(1):24–36.

https://en.wikipedia.org/wiki/Tobit_model

See Also

gammamle, normal.mle

Examples

x <- rnorm(300, 3, 5)
x[ x < 0 ] <- 0   ## left censoring. Values below zero become zero
for (i in 1:50) tobit.mle(x)

Moment and maximum likelihood estimation of variance components

Description

Moment and maximum likelihood estimation of variance components.

Usage

rint.mle(x, ina, ranef = FALSE, tol = 1e-09, maxiters = 100)
varcomps.mom(x, ina)
varcomps.mle(x, ina, tol = 1e-09)

Arguments

x

A numerical vector with the data.

ranef

Should the random effects be returned as well? The default value is FALSE.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero. Alternatively it can be a factor variable.

tol

The tolerance level to terminate the golden ratio search. the default value is 10^(-9).

maxiters

The maximum number of iterations Newton-Raphson will implement.

Details

Note that the "varcomps.mle" and "varcomp.mom" work for balanced designs only, i.e. for each subject the same number of measurements have been taken. The "rint.mle" works for both the balanced and unbalanced designs.

The variance components, the variance of the between measurements and the variance of the within are estimated using moment estimators. The "colvarcomsp.mom" is the moment analogue of a random effects model which uses likelihood estimation ("colvarcomps.mle"). It is much faster, but can give negative variance of the random effects, in which case it becomes zero.

The maximum likelihood version is a bit slower (try youselves to see the difference), but statistically speaking is to be preferred when small samples are available. The reason why it is only a little bit slower and not a lot slower as one would imagine is because we are using a closed formula to calculate the two variance components (Demidenko, 2013, pg. 67-69). Yes, there are closed formulas for linear mixed models.

Value

For the "varcomps.mom": A vector with 5 elemets, The MSE, the estimate of the between variance, the variance components ratio and a 95% confidence for the ratio.

For the "varcomps.mle": a list with a single component called "info". That is a matrix with 3 columns, The MSE, the estimate of the between variance and the log-likelihood value. If ranef = TRUE a list including "info" and an extra component called "ranef" containing the random effects. It is a matrix with the same number of columns as the data. Each column contains the randome effects of each variable.

Author(s)

Michail Tsagris and Manos Papadakis.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Montgomery D.C. (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons.

Davis C.S. (2002). Statistical methods for the analysis of repeated measures. New York: Springer-Verlag.

Demidenko E. (2013). Mixed Models: Theory and Applications with R 2nd Edition). New Jersey: John Wiley & Sons (Excellent book).

See Also

colvarcomps.mle, rint.reg, rint.regbx

Examples

## example from Montgomery, pages 514-517
x <- c(98,97,99,96,91,90,93,92,96,95,97,95,95,96,99,98)
ina <- rep(1:4, each = 4)
res<-varcomps.mom(x, ina)
res<-varcomps.mle(x, ina)

Multi-sample tests for vectors

Description

Multi-sample tests for vectors.

Usage

ftest(x, ina, logged = FALSE)
anova1(x, ina, logged = FALSE)
kruskaltest(x, ina, logged = FALSE) 
var2test(x, y, alternative = "unequal", logged = FALSE)
mcnemar(x, y, logged = FALSE)
ttest2(x, y, paired = FALSE, logged = FALSE)
cqtest(x, treat, block, logged = FALSE) 
block.anova(x, treat, block, logged = FALSE) 
twoway.anova(y, x1, x2, interact = FALSE, logged = FALSE)

Arguments

x

A numerical vector with the data.

y

A numerical vector with the data.

ina

A numerical vector with 1s, 2s, 3s and so one indicating the two groups. Be careful, the function is desinged to accept numbers greater than zero. Alternatively it can be a factor variable.

paired

This is for the two sample t-test only and is TRUE or FALSE specifying whether the two samples are paired or not.

alternative

This can either be "unequal", "greater" or "less".

treat

In the case of the blocking ANOVA and Cochran's Q test, this argument plays the role of the "ina" argument.

block

This item (in the blocking ANOVA and Cochran's Q test) denotes the subjects which are the same. Similarly to "ina" a numeric vector with 1s, 2s, 3s and so on.

x1

The first factor in the two way ANOVA.

x2

The second factor in the two way ANOVA. The orderis not important.

interact

Should interaction in the two way ANOVA be included? The default value is FALSE (no interaction).

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The Welch's F-test (without assuming equal variances) is performed with the "ftest" function. The "anova" function perform the classical (Fisher's) one-way analysis of variance (ANOVA) which assumes equal variance across the groups. The "kruskaltest" performs the Kruskal-Wallis non parametric alternative to analysis of variance test. The "var2tests" implement the classical F test for the equality of two sample variances. The "cqtest" performs the Cocrhan's Q test for the equality of more than two groups whose values are strictly binary (0 or 1). This is a generalisation of the McNemar's test in the multi-sample case. The "block.anova" is the ANOVA with blocking, randomised complete block design (RCBD). In this case, for every combination of the block and treatment values, there is only one observation. The mathematics are the same as in the case of "twoway.anova", but the assumptions different and the testing procedure also different. In addition, no interaction is present.

Value

A vector with the test statistic and the p-value of each test. For the case of t-test, an extra column with the degrees of freedom is given. For the two way ANOVA there can can be either 2 or three F test statistics and hence the same number of p-values.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

B.L. Welch (1951). On the comparison of several mean values: an alternative approach. Biometrika, 38(3/4), 330-336.

D.C. Montgomery (2001). Design and analysis of experiments (5th Edition). New York: John Wiley & Sons.

McNemar Q. (1947). Note on the sampling error of the difference between correlated proportions or percentages. Psychometrika. 12(2):153-157.

See Also

ttests, ftests

Examples

x <- rnorm(200)
ina <- rbinom(200, 3, 0.5) + 1
res<-anova1(x, ina)
res<-ftest(x, ina)
ina <- rbinom(200, 1, 0.5) + 1
x1 <- x[ ina == 1 ]   ; x2 <- x[ ina == 2 ]
res<-ttest2(x1, x2)
res<-var2test(x1, x2)

## RCBD example 4.1 from Montgomery (2001), page 131-132
x <- c(9.3, 9.4, 9.2, 9.7, 9.4, 9.3, 9.4, 9.6, 9.6, 9.8, 9.5, 10,
10, 9.9, 9.7, 10.2)
tr <- rep(1:4, 4)
bl <- rep(1:4, each = 4)
res<-block.anova(x, tr, bl)

Multinomial regression

Description

Multinomial regression.

Usage

multinom.reg(y, x, tol = 1e-07, maxiters = 50)

Arguments

y

The response variable. A numerical or a factor type vector.

x

A matrix or a data.frame with the predictor variables.

tol

This tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The maximum number of iterations Newton-Raphson will perform.

Value

A list including:

iters

The number of iterations required by the Newton-Raphson.

loglik

The value of the maximised log-likelihood.

be

A matrix with the estimated regression coefficients.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Bohning, D. (1992). Multinomial logistic regression algorithm. Annals of the Institute of Statistical Mathematics, 44(1): 197-200.

See Also

glm_logistic, score.multinomregs logistic_only

Examples

y <- iris[, 5]
x <- matrnorm(150, 3)
res <- multinom.reg(y, x)

Multivariate kurtosis

Description

Multivariate kurtosis.

Usage

mvkurtosis(x)

Arguments

x

A numerical matrix.

Details

The multivariate kurtosis is calcualted.

Value

A number, the multivariate kurtosis.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

K. V. Mardia (1970). Measures of Multivariate Skewness and Kurtosis with Applications Biometrika, 57(3):519-530.

See Also

colskewness, skew.test2, colmeans, colVars, colMedians

Examples

x <- as.matrix(iris[, 1:4])
res<-mvkurtosis(x)

Multivariate Laplace random values simulation

Description

Multivariate Laplace random values simulation.

Usage

rmvlaplace(n, lam, mu, G, seed = NULL)

Arguments

n

The sample size, a numerical value.

lam

The the parameter of the exponential distribution, a positive number.

mu

The mean vector.

G

A d×dd \times d covariance matrix with determinant 1.

seed

If you want the same to be generated again use a seed for the generator, an integer number.

Details

The algorithm uses univariate normal random values and transforms them to multivariate via a spectral decomposition.

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Eltoft T., Kim T., and Lee T.W. (2006). On the multivariate laplace distribution. Signal Processing Letters, IEEE, 13(5):300-303.

See Also

rmvnorm, racg, rmvt

Examples

m <- colmeans( as.matrix( iris[, 1:4] ) )
s <- cov(iris[,1:4])
s <- s / det(s)^0.25
lam <- 3
x <- rmvlaplace(100, lam, m, s)

Multivariate normal and t random values simulation

Description

Multivariate normal and t random values simulation.

Usage

rmvnorm(n, mu, sigma, seed = NULL)
rmvt(n, mu, sigma, v, seed = NULL)

Arguments

n

The sample size, a numerical value.

mu

The mean vector in RdR^d.

sigma

The covariance matrix in RdR^d.

v

The degrees of freedom.

seed

If you want the same to be generated again use a seed for the generator, an integer number.

Details

The algorithm uses univariate normal random values and transforms them to multivariate via a spectral decomposition. It is faster than the command "mvrnorm" available from MASS, and it allows for singular covariance matrices.

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.

See Also

racg, rmvlaplace, rmvt

Examples

x <- as.matrix(iris[, 1:4])
m <- colmeans(x)
s <- cov(x)
y <- rmvnorm(1000, m, s)
res<-colmeans(y)
res<-cov(y)
y <- NULL

Naive Bayes classifiers

Description

Gaussian, Poisson, geometric and multinomial naive Bayes classifiers.

Usage

gaussian.nb(xnew = NULL, x, ina, parallel = FALSE)
poisson.nb(xnew, x, ina)
multinom.nb(xnew, x, ina) 
geom.nb(xnew, x, ina, type = 1)
gammanb(xnew = NULL, x, ina, tol = 1e-07)

Arguments

xnew

A numerical matrix with new predictor variables whose group is to be predicted. For the Gaussian naive Bayes, this is set to NUUL, as you might want just the model and not to predict the membership of new observations. For the Gaussian case this contains any numbers, but for the multinomial and Poisson cases, the matrix must contain integer valued numbers only.

x

A numerical matrix with the observed predictor variable values. For the Gaussian case this contains any numbers, but for the multinomial and Poisson cases, the matrix must contain integer valued numbers only.

ina

A numerical vector with strictly positive numbers, i.e. 1,2,3 indicating the groups of the dataset. Alternatively this can be a factor variable.

type

Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1. This is for the geometric distribution. This argument is for the geometric distribution. Type 1 refers to the case where the minimum is zero and type 2 for the case of the minimum being 1.

tol

The tolerance value to terminate the Newton-Raphson algorithm in the gamma distribution.

parallel

If you want parallel computations set this equal to TRUE.

Value

For the Poisson and Multinomial naive Bayes classifiers the estimated group, a numerical vector with 1, 2, 3 and so on. For the Gaussian naive Bayes classifier a list including:

mu

A matrix with the mean vector of each group based on the dataset.

sigma

A matrix with the variance of each group and variable based on the dataset.

ni

The sample size of each group in the dataset.

est

The estimated group of the xnew observations. It returns a numerical value back regardless of the target variable being numerical as well or factor. Hence, it is suggested that you do \"as.numeric(target)\" in order to see what is the predicted class of the new data.

For the Gamma classifier a list including:

a

A matrix with the shape parameters.

b

A matrix with the scale parameters.

est

The estimated group of the xnew observations. It returns a numerical value back regardless of the target variable being numerical as well or factor. Hence, it is suggested that you do \"as.numeric(target)\" in order to see what is the predicted class of the new data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

gaussiannb.pred, colmeans, colVars

Examples

x <- as.matrix(iris[, 1:4])
a <- gaussian.nb(x, x, iris[, 5])
x1 <- matrix( rpois(100 * 4, 5), ncol = 4)
x2 <- matrix( rpois(50 * 4, 10), ncol = 4)
x <- rbind(x1, x2)
ina <- c( rep(1, 100), rep(2, 50) )
res<-poisson.nb(x, x, ina)
res<-geom.nb(x, x, ina)
res<-multinom.nb(x, x, ina)

Natural Logarithm each element of a matrix

Description

Natural Logarithm each element of a matrix.

Usage

Log(x, na.rm = FALSE)

Arguments

x

A matrix with data.

na.rm

A boolean value (TRUE/FALSE) for removing NA.

Details

The argument must be a matrix. For vector the time was the same as R's "log" function so we did not add it.

Value

A matrix where each element is the natural logarithm of the given argument.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Lbeta, Lchoose, Choose

Examples

x <-matrix( runif( 100 * 100), ncol = 100 )
a <- log(x) 
b <- Log(x) 
all.equal(a, b) # true

x<-a<-b<-NULL

Natural logarithm of the beta function

Description

Natural logarithm of the beta function.

Usage

Lbeta(x, y)

Arguments

x

A numerical matrix, or a vector or just a number with positive numbers in either case.

y

A numerical matrix, or a vector or just a number with positive numbers in either case. The dimensions of y must match those of x.

Details

The function is faster than R's lbeta when the dimensions of x any are large. If you have only two numbers, then lbeta is faster. But if you have for example two vectors of 1000 values each, Lbeta becomes two times faster than lbeta.

Value

The matrix, vector or number with the resulting values.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Abramowitz, M. and Stegun, I. A. (1972) Handbook of Mathematical Functions. New York: Dover. https://en.wikipedia.org/wiki/Abramowitz_and_Stegun provides links to the full text which is in public domain. Chapter 6: Gamma and Related Functions.

See Also

Lgamma, beta.mle, diri.nr2

Examples

x <- rexp(1000)
y <- rexp(1000)
a1 <- Lbeta(x, y)

x<-y<-a1<-NULL

Natural logarithm of the gamma function and its derivatives.

Description

Natural logarithm of the gamma function and its derivatives.

Usage

Lgamma(x)
Digamma(x)
Trigamma(x)

Arguments

x

A numerical matrix or vector with positive numbers in either case.

Details

We have spotted that the time savings come when there are more than 50 elements, with vector or matrix.

Value

The matrix or the vector with the resulting values.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Abramowitz, M. and Stegun, I. A. (1972) Handbook of Mathematical Functions. New York: Dover. https://en.wikipedia.org/wiki/Abramowitz_and_Stegun provides links to the full text which is in public domain. Chapter 6: Gamma and Related Functions.

See Also

beta.mle, diri.nr2

Examples

x <- matrix( rnorm(500 * 500), ncol = 500 )
 a1 <- Lgamma(x) 
a2 <- lgamma(x) 
all.equal(as.vector(a1), as.vector(a2))

a1 <- Digamma(x) 
a2 <- digamma(x) 
all.equal(as.vector(a1), as.vector(a2))

x<-a1<-a2<-NULL

Norm of a matrix

Description

Norm of a matrix.

Usage

Norm(x, type = "F")

Arguments

x

A matrix with numbers.

type

The type of norm to be calculated. The default is "F" standing for Frobenius norm ("f" in R's norm). The other options are "C" standing for the one norm ("o" in R's norm), "R" for the identiy norm ("I" in R's norm) and "M" for the maximum modulus among elements of a matrix ("M" in R's norm)

Value

A number, the norm of the matrix.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Dist, dista, colmeans

Examples

x <- matrix( rnorm(10 * 10), ncol = 10 )
res<-Norm(x, "F")
res<-norm(x, "F")
res<-Norm(x, "M")
res<-norm(x, "M")

Number of equal columns between two matrices

Description

Number of equal columns between two matrices.

Usage

mat.mat(x, y)

Arguments

x

A numerical matrix. See details for more information. It must have the same number of rows as y.

y

A numerical matrix. See details for more information. It must have the same number of rows as x.

Details

The function takes each column of x and checks the number of times it matches a column of y. In the example below, we take the first 3 columns of iris as the x matrix. The y matrix is the whole of iris. We will see how many times, each column of x appears in the y matrix. The answer is 1 for each column.

Value

A numerical vector of size equal to the number of columns of x.

Author(s)

Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

Match, colmeans, colMedians

Examples

x <- as.matrix(iris[, 1:3])
y <- iris
y[, 5] <- as.numeric(y[, 5])
y <- as.matrix(y)
res<-mat.mat(x, y)

x<-y<-NULL

Odds ratio and relative risk

Description

Odds ratio and relative risk.

Usage

odds.ratio(x, a = 0.05, logged = FALSE)
rel.risk(x, a = 0.05, logged = FALSE)

Arguments

x

A 2 x 2 matrix or a vector with 4 elements. In the case of the vector make sure it corresponds to the correct table.

a

The significance level, set to 0.05 by default.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

The odds ratio and the confidence interval are calculated.

Value

A list including:

res

The estimated odds ratio and the p-value for the null hypothesis test that it is equal to 1.

ci

The (1-a)% confidence interval for the true value of the odds ratio.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Mosteller Frederick (1968). Association and Estimation in Contingency Tables. Journal of the American Statistical Association. 63(321):1-28.

Edwards A.W.F. (1963). The measure of association in a 2x2 table. Journal of the Royal Statistical Society, Series A. 126(1):109-114.

See Also

odds, g2Test

Examples

x <- rpois(4, 30)+2
res<-odds.ratio(x)
res<-odds.ratio( matrix(x, ncol = 2) )

One sample t-test for a vector

Description

One sample t-test for a vector.

Usage

ttest1(x, m, alternative = "unequal", logged = FALSE, conf = NULL)

Arguments

x

A numerical vector with the data.

m

The mean value under the null hypothesis.

alternative

The alternative hypothesis, "unequal", "greater" or "less".

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

conf

If you want a confidence interval supply the confidence level.

Details

The usual one sample t-test is implemented, only faster.

Value

A list including:

res

A two valued vector with the test statistic and its (logged) p-value.

ci

In the case you supplied a number in the input argument "conf" the relevant confidence interval will be returned as well.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

See Also

ttest, anova1, ttests

Examples

x = rnorm(500)
res<-t.test(x, mu = 0)
res<-ttest1(x, 0, conf = 0.95)

Operations between two matrices or matrix and vector

Description

Operations between two matrices or matrix and vector.

Usage

XopY.sum(x, y = NULL, oper = "*")
eachrow(x,y,oper = "*",method = NULL)
eachcol.apply(x,y,indices = NULL,oper = "*",apply = "sum", parallel = FALSE)

Arguments

x

A numerical matrix.

y

A second numerical matrix for "XopY.sum" whose dimensions must match the ones of x, or vector for "eachrow","eachcol.apply" whose length must match with the rows of x.

oper

The operation to be performed, either "*", "/", "+", "-" or "==".

method

A character value for choosing option to apply in the result. Options: 1) sum 2) max 3) min

Does not work for oper="==".

indices

An integer vector with indices to specific columns. Only for "eachcol.apply".

apply

A character value with the function to be applied in the columns of the matrix. Only for "eachcol.apply". Options: 1) sum 2) median 3) max 4) min

parallel

A boolean value for parallel version.

Details

XopY.sum: sum(X op Y) where op can be on of "+,-,*,/".

eachrow: X op Y by row or FUNCTION(X op Y) where "x" is matrix, "y" is vector with length as much an the columns of x and "op" is one of "+,-,*,/,==", and "FUNCTION" is a specific method for applying in the result matrix (see argument method).

eachcol.apply: FUNCTION(X op Y) by column where "x" is matrix, "y" is vector with length as much an the rows of x, "op" is one of "+,-,*,/" and "FUNCTION" is a specific method (see argument apply).

NOTE: Arguments "method" does not work for oper="==" and this operation works only in "eachrow".

Value

XopY.sum: sum(X op Y) where "op" can be on of "+,-,*,/".

eachrow: operation by row between a matrix and a vector."op" can be on of "+,-,*,/". If "suma=TRUE" then returns the sum of this operation.

eachcol.apply: operation by column between a matrix and a vector and applied a specific function."op" can be on of "+,-,*,/".

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Dist, dista, colmeans, Diag.fill, colMads, rowMads

Examples

x <- matrix( rnorm(5 * 5), ncol = 5 )
y <- matrix( rnorm(5 * 5), ncol = 5 )
res<-XopY.sum(x, y, oper = "*")
y <- x[,1]
res<-eachrow(x,y)

all.equal(eachcol.apply(x,y),colsums(x*y))


x<-y<-NULL

Orthogonal matching pursuit variable selection

Description

Orthogonal matching pursuit variable selection.

Usage

ompr(y, x, ystand = TRUE, xstand = TRUE, method = "BIC", tol = 2 )
omp(y, x, xstand = TRUE, tol = qchisq(0.95, 1) + log( length(y) ), type = "logistic" )

Arguments

y

The response variable, a numeric vector. For "ompr" this is a continuous variable. For "omp" this can be either a vector with discrete (count) data, 0 and 1, non negative values, strictly positive or proportions including 0 and 1.

x

A matrix with the data, where the rows denote the observations and the columns are the variables.

ystand

If this is TRUE the response variable is centered. The mean is subtracted from every value.

xstand

If this is TRUE the independent variables are standardised.

method

You can choose between the change in the BIC ("BIC"), the adjusted R2R^2 ("ar2"), the SSE ("SSE") or the classical p-value based ("pvalue").

tol

The tolerance value to terminate the algorithm. This is the change in the criterion value between two successive steps. For "ompr" the default value is 2 because the default method is "BIC". For "omp" the default value is the 95% quantile of the χ2\chi^2 distribution with 1 degree of freedom plus the logarithm of the sample size.

type

This denotes the parametric model to be used each time. It depends upon the nature of y. The possible values are "logistic", "poisson", "quasipoisson", "quasibinomial", "normlog", "gamma", "weibull", "mv" (for multivariate response variable) or "multinomial".

Value

For "ompr" a list including:

runtime

The runtime of the algorithm.

info

A matrix with two columns. The selected variable(s) and the criterion value at every step.

For "omp" a list including:

runtime

The runtime of the algorithm.

phi

The ϕ\phi parameter. In the cases of "quasipoisson", "quasibinomial" and "normlog" this is useful. For all other cases this is NULL.

info

A matrix with two columns. The selected variable(s) and the criterion value at every step.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Pati Y. C., Rezaiifar R. & Krishnaprasad P. S. (1993). Orthogonal matching pursuit: Recursive function approximation with applications to wavelet decomposition. In Signals, Systems and Computers. 1993 Conference Record of The Twenty-Seventh Asilomar Conference on. IEEE.

Mazin Abdulrasool Hameed (2012). Comparative analysis of orthogonal matching pursuit and least angle regression. MSc thesis, Michigan State University. https://www.google.gr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwik9P3Yto7XAhUiCZoKHQ8XDr8QFgglMAA&url=https

Lozano A., Swirszcz G., & Abe N. (2011). Group orthogonal matching pursuit for logistic regression. In Proceedings of the Fourteenth International Conference on Artificial Intelligence and Statistics.

The γ\gamma-OMP algorithm for feature selection with application to gene expression data. IEEE/ACM Transactions on Computational Biology and Bioinformatics (Accepted for publication) https://arxiv.org/pdf/2004.00281.pdf

See Also

cor.fbed, cor.fsreg, correls, fs.reg

Examples

x <- matrnorm(100, 400)
y <- rnorm(100)
a <- ompr(y, x)
a
x <- NULL

Outer function

Description

The outer function.

Usage

Outer(x, y, oper = "*")

Arguments

x

A numerical vector.

y

A numerical vector.

oper

The available options are "*" (multiplication), "/" (division), "+" (sum), "-" (substraction), "^" (power raise), and "

Details

The function is the same as R's "outer", but works with vectors only and probably has less capabilities, but faster.

Value

A matrix with all the combinations.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

See Also

mat.mult, vecdist

Examples

x <- rnorm(10)
y <- rnorm(10)
res<-Outer(x, y)

Permutation based p-value for the Pearson correlation coefficient

Description

Permutation based p-value for the Pearson correlation coefficient.

Usage

permcor(x, y, R = 999)

Arguments

x

A numerical vector with the first variable.

y

A numerical vector with the second variable.

R

The number of permutations to be conducted; set to 999 by default.

Details

This is a very low computational calculation of the p-value. Try it yourselves.

Value

A vector consisting of two values, the Pearson correlation and the permutation based p-value.

Author(s)

Marios Dimitriadis and Michail Tsagris

R implementation and documentation: Marios Dimitriadis and Michail Tsagris <[email protected]> and <[email protected]>

References

Chatzipantsiou C., Dimitriadis M., Papadakis M. and Tsagris M. (2019). Extremely efficient permutation and bootstrap hypothesis tests using R. To appear in the Journal of Modern Applied Statistical Methods.

https://arxiv.org/ftp/arxiv/papers/1806/1806.10947.pdf

See Also

pc.skel

Examples

x <- iris[, 1]
y <- iris[, 2]
res<-permcor(x, y)
res<-permcor(x, y, R = 9999)

Polyserial correlation

Description

Polyserial correlation.

Usage

poly.cor(x, y)

Arguments

x

The continuous variable.

y

The ordinal variable, a numeric vector with numbers starting from 1.

Details

The polyserial correlation between a continuous and an ordinal variable is calculated. The function is not super fast, yet is faster than other implementations we found.

Value

A list including:

est

A vector with the polyserial correlation and its estimated variance.

test

A vector with the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Olsson U., Drasgow F. and Dorans N. J. (1982). The polyserial correlation coefficient. Psychometrika, 47(3):337-347.

See Also

correls, Table

Examples

x <- rnorm(100)
y <- rpois(100, 10) + 1
res<-poly.cor(x, y)

Pooled covariance matrix

Description

Pooled covariance matrix.

Usage

pooled.cov(x, ina)

Arguments

x

A matrix with continuous data.

ina

A numerical vector indicating the groups. The nubmers must be consecutive and start from 1.

Details

The spatial median is at first computed (if not supplied) and then the covariance matrix.

Value

The spatial sign covariance matrix.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Durre A, Vogel D. and D.E. Tyler D.E.(2014). The spatial sign covariance matrix with unknown location. Journal of Multivariate Analysis, 130: 107-117. http://arxiv.org/pdf/1307.5706v2.pdf

See Also

spat.med, spatmed.reg

Examples

res<-sscov( as.matrix(iris[, 1:4]) )

Prediction with some naive Bayes classifiers

Description

Prediction with some naive Bayes classifiers.

Usage

gaussiannb.pred(xnew, m, s, ni)
poissonnb.pred(xnew, m)
multinomnb.pred(xnew, m)  
gammanb.pred(xnew, a, b)  
geomnb.pred(xnew, prob)

Arguments

xnew

A numerical matrix with new predictor variables whose group is to be predicted. For the Gaussian case this contains any numbers, but for the multinomial and Poisson cases, the matrix must contain integer valued numbers only.

m

A matrix with the group means. Each row corresponds to a group.

s

A matrix with the group colum-wise variances. Each row corresponds to a group.

ni

A vector with the frequencies of each group.

a

A vector with the shape parameters of each group.

b

A vector with the scale parameters of each group.

prob

A vector with the sprobability parameters of each group.

Value

A numerical vector with 1, 2, ... denoting the predicted group.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

gaussian.nb, colpoisson.mle colVars

Examples

ina <- sample(1:150, 100)
x <- as.matrix(iris[, 1:4])
id <- as.numeric(iris[, 5])
a <- gaussian.nb(xnew = NULL, x[ina, ], id[ina])
est <- gaussiannb.pred(x[-ina, ], a$mu, a$sigma, a$ni)
res<-table(id[-ina], est)

Quasi binomial regression for proportions

Description

Quasi binomial regression for proportions.

Usage

prop.reg(y, x, varb = "quasi", tol = 1e-09, maxiters = 100) 
prop.regs(y, x, varb = "quasi", tol = 1e-09, logged = FALSE, maxiters = 100)

Arguments

y

A numerical vector proportions. 0s and 1s are allowed.

x

For the "prop.reg" a matrix with data, the predictor variables. This can be a matrix or a data frame. For the "prop.regs" this must be a numerical matrix, where each columns denotes a variable.

tol

The tolerance value to terminate the Newton-Raphson algorithm. This is set to 10910^{-9} by default.

varb

The type of estimate to be used in order to estimate the covariance matrix of the regression coefficients. There are two options, either "quasi" (default value) or "glm". See the references for more information.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

maxiters

The maximum number of iterations before the Newton-Raphson is terminated automatically.

Details

We are using the Newton-Raphson, but unlike R's built-in function "glm" we do no checks and no extra calculations, or whatever. Simply the model. The "prop.regs" is to be used for very many univariate regressions. The "x" is a matrix in this case and the significance of each variable (column of the matrix) is tested. The function accepts binary responses as well (0 or 1).

Value

For the "prop.reg" function a list including:

iters

The number of iterations required by the Newton-Raphson.

varb

The covariance matrix of the regression coefficients.

phi

The phi parameter is returned if the input argument "varb" was set to "glm", othwerise this is NULL.

info

A table similar to the one produced by "glm" with the estimated regression coefficients, their standard error, Wald test statistic and p-values.

For the "prop.regs" a two-column matrix with the test statistics (Wald statistic) and the associated p-values (or their loggarithm).

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Papke L. E. & Wooldridge J. (1996). Econometric methods for fractional response variables with an application to 401(K) plan participation rates. Journal of Applied Econometrics, 11(6): 619–632.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

anova_propreg univglms, score.glms, logistic_only

Examples

y <- rbeta(100, 1, 4)
x <- matrix(rnorm(100 * 3), ncol = 3)
a <- prop.reg(y, x)
y <- rbeta(100, 1, 4)
x <- matrix(rnorm(400 * 100), ncol = 400)
b <- prop.regs(y, x)
res<-mean(b[, 2] < 0.05)

Quasi Poisson regression

Description

Quasi Poisson regression.

Usage

qpois.reg(x, y, full = FALSE, tol = 1e-09,maxiters = 100) 
qpois.regs(x, y, tol = 1e-09, logged = FALSE)

Arguments

x

For the "qpois.reg" a matrix with data, the predictor variables. This can be a matrix or a data frame. For the "qpois.regs" this must be a numerical matrix, where each columns denotes a variable.

y

A numerical vector with positive discrete data.

full

If this is FALSE, the coefficients, the deviance and the estimated phi parameter will be returned only. If this is TRUE, more information is returned.

tol

The tolerance value to terminate the Newton-Raphson algorithm. This is set to 10910^{-9} by default.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

maxiters

The maximum number of iterations before the Newton-Raphson is terminated automatically.

Details

We are using the Newton-Raphson, but unlike R's built-in function "glm" we do no checks and no extra calculations, or whatever. Simply the model, unless the user requests for the Wald tests of the coefficients. The "qpois.regs" is to be used for very many univariate regressions. The "x" is a matrix in this case and the significance of each variable (column of the matrix) is tested.

Value

For the "prop.reg" a list including: When full is FALSE

be

The regression coefficients.

devi

The deviance of the model.

varb

The covariance matrix of the beta coefficients.

phi

The phi parameter, the estimate of dispersion.

When full is TRUE, the additional item is:

info

The regression coefficients, their standard error, their Wald test statistic and their p-value.

For the "prop.regs" a two-column matrix with the test statistics (Wald statistic) and the associated p-values (or their loggarithm).

Author(s)

Manos Papadakis and Marios Dimitriadis

R implementation and documentation: Manos Papadakis <[email protected]> and Marios Dimitriadis <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

prop.reg univglms, score.glms, poisson_only

Examples

y <- rnbinom(100, 10, 0.6)
x <- matrix(rnorm(100*3), ncol = 3)
mod1 <- glm(y ~ x, quasipoisson)
res<-summary(mod1)
res<-qpois.reg(x, y, full = TRUE)
res<-qpois.regs(x, y)

Random intercepts linear mixed models

Description

Random intercepts linear mixed models (for balanced data with a single identical covariate).

Usage

rint.reg(y, x, id ,tol = 1e-08, ranef = FALSE, maxiters = 100)
rint.regbx(y, x, id)

Arguments

y

A numerical vector with the data. The subject values.

x

For the case of "rint.reg" this can be a vector or a numerical matrix with data. In the case of "rint.regbx" this is a numerical vector with the same length as y indicating the fixed predictor variable. Its values are the same for all levels of y. An example of this x is time which is the same for all subjects.

id

A numerical variable with 1, 2, ... indicating the subject.

tol

The tolerance level to terminate the generalised elast squares algorithm.

ranef

If you want to obtain the random effects (random intercepts) set this equal to TRUE.

maxiters

The max number of iterations that can take place in a regression.

Details

Random intercepts linear mixed models with compound covariance structure is fitted in both functions. The "rint.reg" allows any numerical matrix, with balanced or unbalanced data. See Demidenko (2013, pg. 65-67) for more information.

The "rint.regbx" is a special case of a balanced random intercepts model with a compound symmetric covariance matrix and one single covariate which is constant for all replicates. An example, is time, which is the same for all subjects. Maximum likelihood estimation has been performed. In this case the mathematics exist in a closed formula (Demidenko, 2013, pg. 67-69).

Value

A list including:

info

A vector with the random intercepts variance (between), the variance of the errors (within), the log-likelihood, the deviance (twice the log-likelihood) and the BIC. In the case of "rint.reg" it also includes the number of iterations required by the generalised least squares.

be

The estimated regression coefficients, which in the case of "rint.regbx" are simply two: the constant and the slope (time effect).

ranef

The random intercepts effects.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Eugene Demidenko (2013). Mixed Models: Theory and Applications with R, 2nd Edition. New Jersey: Wiley & Sons (excellent book).

See Also

rm.lines, varcomps.mom, colvarcomps.mom

Examples

y <- rnorm(100) 
x <- rnorm(10)
x <- rep(x, 10)
id <- rep(1:10, each = 10)
for (i in 1:20) a <- rint.reg(y, x, id)

Random values simulation from a von Mises distribution

Description

It generates random vectors following the von Mises distribution. The data can be spherical or hyper-spherical.

Usage

rvonmises(n, m, k, rads = TRUE)

Arguments

n

The sample size.

m

The mean angle expressed in radians or degrees.

k

The concentration parameter. If k is zero the sample will be generated from the uniform distribution over (0,2π)(0, 2\pi).

rads

If the mean angle is expressed in radians, this should be TRUE and FALSE otherwise. The simulated data will be expressed in radians or degrees depending on what the mean angle is expressed.

Details

The mean direction is transformed to the Euclidean coordinates (i.e. unit vector) and then the fvmf function is employed. It uses a rejection smapling as suggested by Andrew Wood in 1994. I have mentioned the description of the algorithm as I found it in Dhillon and Sra in 2003. Finally, the data are transformed to radians or degrees.

Value

A vector with the simulated data.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Wood, A. T. (1994). Simulation of the von Mises Fisher distribution. Communications in statistics-simulation and computation, 23(1): 157-164.

Dhillon, I. S., & Sra, S. (2003). Modeling data using directional distributions. Technical Report TR-03-06, Department of Computer Sciences, The University of Texas at Austin. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.75.4122&rep=rep1&type=pdf

See Also

vm.mle, rvmf

Examples

x <- rvonmises(1000, 2, 25, rads = TRUE)
res<-vm.mle(x)

Reading the files of a directory

Description

Reading the files of a directory.

Usage

read.directory(path.directory)
read.examples(path.man)

Arguments

path.directory

The full path to the directory. For example: \"C:\Users\username\Documents\R\Rfast_1.8.0\R\"

path.man

The full path to the directory with the Rd files in it. For example: \"C:\Users\username\Documents\R\Rfast_1.8.0\man\\"

Details

For function \"read.directory\": Takes as an argument a full path to a directory and returns the names of the files.

For function \"read.examples\": Takes as an argument a full path to the directory of the Rd files. If you don't want the program to read any file add at the top of the file the attribute "%[dont read]".

Value

For function \"read.directory\": The names of the files.

For function \"read.examples\": a list with 2 fields

examples

A character vector with the examples of each Rd file.

files

A character vector with the name of the file that each examples belongs.

long_lines

A character vector with the name of the file that has large examples.

You can choose which files not to read for both R and Rd. You must add in the first line of the file in comment the "attribute" "%[dont read]". Finally, that function wil return in the result a list of which files had this attribute.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

AddToNamespace, sourceR, sourceRd, checkRd, checkExamples

Examples

# for example: path="C:\some_file\"
# system.time( read.directory(path) )
# system.time( list.dirs(path) )

# for example: path.man="C:\some_file\man\"
# system.time( read.examples(path.man) )
# system.time( read.examples(path.man,dont.read=c("somef_1.Rd",...,"somef_n.Rd") ) )

Repeated measures anova

Description

Repeated measures anova.

Usage

rm.anova(y, logged = FALSE)

Arguments

y

A matrix with the data, where each column refers to a different measurement. The rows denote the subjects.

logged

Should the p-values be returned (FALSE) or their logarithm (TRUE)?

Details

Found in Davis (2002) is the usual repeated measures ANOVA. In this case, suppose you have taken measurements on one or more variables from the same group of people. See the example below on how to put such data.

Value

A vector with the test statistic (t-test) and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Charles S. Davis (2002). Statistical methods for the analysis of repeated measures. Springer-Verlag, New York.

See Also

rm.anovas, rint.reg, varcomps.mle

Examples

y <- c(74.5,81.5,83.6,68.6,73.1,79.4,
75.5,84.6,70.6,87.3,73.0,75.0,
68.9,71.6,55.9,61.9,60.5,61.8,
57.0,61.3,54.1,59.2,56.6,58.8,
78.3,84.9,64.0,62.2,60.1,78.7,
54.0,62.8,63.0,58.0,56.0,51.5,
72.5,68.3,67.8,71.5,65.0,67.7,
80.8,89.9,83.2,83.0,85.7,79.6)
y <- matrix(y, ncol = 6, byrow = TRUE)
res<-rm.anova(y)

Round each element of a matrix/vector

Description

Round each element of a matrix/vector.

Usage

Round(x,digit=0,na.rm = FALSE)

Arguments

x

A numeric matrix/vector with data or NA. NOT integer values.

digit

An integer value for 0...N-1 where N is the number of the digits. By default is 0.

na.rm

TRUE or FAlSE for remove NAs if exists.

Details

Round is a very fast C++ implementation. Especially for large data. It handles NA.

Value

A vector/matrix where each element is been rounded in the given digit.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Lchoose, Log, Choose

Examples

x <-matrix( rnorm( 50 * 10), ncol = 10 )
a <- Round(x,5)
b <- round(x,5)
all.equal(a,b) #true
x <-rnorm( 1000)
a <- Round(x,5)
b <- round(x,5)
all.equal(a,b) # true

Row - Wise matrix/vector count the frequency of a value

Description

Row - Wise matrix/vector count the frequency of a value.

Usage

count_value(x, value)
colCountValues(x, values, parallel = FALSE,cores = 0)
rowCountValues(x, values, parallel = FALSE,cores = 0)

Arguments

x

A vector with the data (numeric or character) or a numeric matrix.

value

The value, numeric or character, to check its frequency in the vector "x".

values

a vector with the values to check its frequency in the matrix "x" by row or column.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE. Works with every other argument.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Details

The functions is written in C++ in order to be as fast as possible. The "x" and "value" must have the same type. The type can be numeric or character.

Value

The frequency of a value/values in a vector in linear time or by row/column in a matrix.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Median, binary_search, Order, nth

Examples

x <- rnorm(100)
value <- x[50]
count_value(x,value)
y <- sample(letters,replace=TRUE)
value <- "r"
count_value(y,value)
values <- sample(x,100,replace=TRUE)
x <- matrix(x,100,100)
res<-colCountValues(x,values)
res<-rowCountValues(x,values)
x<-value<-values<-y<-NULL

Row-wise minimum and maximum of a matrix.

Description

Row-wise minimum and maximum of a matrix.

Usage

rowMins(x, value = FALSE)
rowMaxs(x, value = FALSE)
rowMinsMaxs(x)

Arguments

x

A numerical matrix with data.

value

If the value is FALSE it returns the indices of the minimum/maximum, otherwise it returns the minimum and maximum values.

Value

A vector with the relevant values.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colMins, colMaxs, nth, rowrange colMedians, colVars, colSort, rowSort

Examples

x <- matrix( rnorm(10 * 10), ncol = 10 )

s1 <- rowMins(x)
#s2 <- apply(x, 1, min)

s1 <- rowMaxs(x)
#s2 <- apply(x, 1, max)

#s1 <- c(apply(x, 1, min),apply(x, 1, max) )
s2 <- rowMinsMaxs(x)

x<-s1<-s2<-NULL

Row-wise true value of a matrix

Description

Row-wise true value of a matrix.

Usage

rowTrue(x)
rowFalse(x)
rowTrueFalse(x)

Arguments

x

A logical matrix with data.

Value

An integer vector where item "i" is the number of the true/false values of "i" row.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

rowMins, colFalse, nth, rowrange, rowMedians, rowVars, colTrue

Examples

x <- matrix(as.logical(rbinom(100*100,1,0.5)),100,100)

s1 <- rowTrue(x) 

s1 <- rowFalse(x)  

s1 <- rowTrueFalse(x)

x<-s1<-NULL

Search for variables with zero range in a matrix

Description

Search for variables with zero range in a matrix.

Usage

check_data(x, ina = NULL)

Arguments

x

A matrix or a data.frame with the data, where rows denotes the observations and the columns contain the dependent variables.

ina

If your data are grouped, for example there is a factor or numerical variable indicating the groups of the data supply it here, otherwise leave it NULL.

Details

The function identifies the variabels with zero range, instead of a zero variance as this is faster. It will work with matrices and data.frames.

Value

A numerical vector of length zero if no zero ranged variable exists, or of length at least one with the index (or indices) of the variable(s) that need attention or need to be removed.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colrange, colVars

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
res<-check_data(x)

## some variables have a constant value
x[, c(1,10, 50, 70)] <- 1
res<-check_data(x)
id <- rep(1:4, each = 25 )
x[1:25, 2] <- 0
res<-check_data(x)  ## did not use the id variable
res<-check_data(x, id)  ## see now
x <- NULL

Significance testing for the coefficients of Quasi binomial or the quasi Poisson regression

Description

Significance testing for the coefficients of Quasi binomial or the quasi Poisson regression.

Usage

anova_propreg(mod, poia = NULL)
anova_qpois.reg(mod, poia = NULL)

Arguments

mod

An object as returned by the "prop.reg" or the "qpois.reg" function.

poia

If you want to test the significance of a single coefficient this must be a number. In this case, the "prop.reg" or the "qpois.reg" function contains this information. If you want more coefficients to be testes simultaneously, e.g. for a categorical predictor, then this must contain the positions of the coefficients. If you want to see if all coefficients are zero, like an overall F-test, leave this NULL.

Details

Even though the name of this function starts with anova it is not an ANOVA type significance testing, but a Wald type.

Value

A vector with three elements, the test statistic value, its associated p-value and the relevant degrees of freedom.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Papke L. E. & Wooldridge J. (1996). Econometric methods for fractional response variables with an application to 401(K) plan participation rates. Journal of Applied Econometrics, 11(6): 619-632.

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

prop.reg, qpois.reg, univglms, score.glms, logistic_only

Examples

y <- rbeta(1000, 1, 4)
x <- matrix(rnorm(1000 * 3), ncol = 3)
a <- prop.reg(y, x)
## all coefficients are tested
res<-anova_propreg(a)  
## the first predictor variable is tested 
res<-anova_propreg(a, 2)  
a  ## this information is already included in the model output
## the first and the second predictor variables are tested 
res<-anova_propreg(a, 2:3)

Simulating from a Bingham distribution

Description

Simulation from a Bingham distribution using the code suggested by Kent et al. (2013).

Usage

rbing(n, lam)

Arguments

n

Sample size.

lam

Eigenvalues of the diagonal symmetric matrix of the Bingham distribution. See details for more information on this.

Details

The user must have calculated the eigenvalues of the diagonal symmetric matrix of the Bingham distribution. The function accepts the q-1 eigenvalues only. This means, that the user must have subtracted the lowest eigenvalue from the rest and give the non zero ones. The function uses rejection sampling.

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Kent J.T., Ganeiber A.M. and Mardia K.V. (2013). A new method to simulate the Bingham and related distributions in directional data analysis with applications. http://arxiv.org/pdf/1310.8110v1.pdf

C.J. Fallaize and T. Kypraios (2014). Exact Bayesian Inference for the Bingham Distribution. Statistics and Computing (No volum assigned yet). http://arxiv.org/pdf/1401.2894v1.pdf

See Also

rvmf

Examples

x <- rbing( 100, c(1, 0.6, 0.1) )
x

Simulation of random values from a Bingham distribution with any symmetric matrix

Description

Simulation of random values from a Bingham distribution with any symmetric matrix.

Usage

rbingham(n, A)

Arguments

n

Sample size.

A

A symmetric matrix.

Details

The eigenvalues of the q x q symmetric matrix A are calculated and the smallest of them is subtracted from the rest. The q - 1 non zero eiqenvalues are then passed to rbing. The generated data are then right multiplied by VTV^T, where V is the matrix of eigenvectors of the matrix A.

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Kent J.T., Ganeiber A.M. and Mardia K.V. (2013). A new method to simulate the Bingham and related distributions in directional data analysis with applications. http://arxiv.org/pdf/1310.8110v1.pdf

C.J. Fallaize and T. Kypraios (2014). Exact Bayesian Inference for the Bingham Distribution. Statistics and Computing (No volum assigned yet). http://arxiv.org/pdf/1401.2894v1.pdf

See Also

rvmf

Examples

A <- cov( iris[, 1:4] )
x <- rbingham(100, A)
x

Simulation of random values from a normal distribution

Description

Simulation of random values from a normal distribution.

Usage

Rnorm(n, m = 0, s = 1, seed = NULL)

Arguments

n

The sample size.

m

The mean, set to 0 by default.

s

The standard devation, set to 1 by default.

seed

If you want the same to be generated again use a seed for the generator, an integer number.

Details

By using the Ziggurat method of generating standard normal variates, this function is really fast when you want to generate large vectors. For less than 2,000 this might make no difference when compared with R's "rnorm", but for 10,000 this will be 6-7 times faster.

Value

A vector with n values.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

See Also

matrnorm, rvonmises, rvmf, rmvnorm

Examples

x <- Rnorm(500)

Random values simulation from a von Mises-Fisher distribution

Description

It generates random vectors following the von Mises-Fisher distribution. The data can be spherical or hyper-spherical.

Usage

rvmf(n, mu, k)

Arguments

n

The sample size.

mu

The mean direction, a unit vector.

k

The concentration parameter. If k = 0, random values from the spherical uniform will be drwan. Values from a multivariate normal distribution with zero mean vector and the identity matrix as the covariance matrix. Then each vector becomes a unit vector.

Details

It uses a rejection smapling as suggested by Andrew Wood (1994).

Value

A matrix with the simulated data.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Wood A. T. A. (1994). Simulation of the von Mises Fisher distribution. Communications in statistics-simulation and computation, 23(1): 157–164.

Dhillon I. S. & Sra S. (2003). Modeling data using directional distributions. Technical Report TR-03-06, Department of Computer Sciences, The University of Texas at Austin. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.75.4122&rep=rep1&type=pdf

See Also

vmf.mle, rvonmises, iag.mle

Examples

m <- rnorm(4)
m <- m/sqrt(sum(m^2))
x <- rvmf(1000, m, 25)
m
res<-vmf.mle(x)

The skeleton of a Bayesian network produced by the PC algorithm

Description

The skeleton of a Bayesian network produced by the PC algorithm.

Usage

pc.skel(dataset, method = "pearson", alpha = 0.01, R = 1, stat = NULL, ini.pvalue = NULL)

Arguments

dataset

A numerical matrix with the variables. If you have a data.frame (i.e. categorical data) turn them into a matrix using data.frame.to_matrix. Note, that for the categorical case data, the numbers must start from 0. No missing data are allowed.

method

If you have continuous data, you can choose either "pearson" or "spearman". If you have categorical data though, this must be "cat". In this case, make sure the minimum value of each variable is zero. The g2Test and the relevant functions work that way.

alpha

The significance level (suitable values in (0, 1)) for assessing the p-values. Default (preferred) value is 0.01.

R

The number of permutations to be conducted. The p-values are assessed via permutations. Use the default value if you want no permutation based assessment.

stat

If the initial test statistics (univariate associations) are available, pass them through this parameter.

ini.pvalue

if the initial p-values of the univariate associations are available, pass them through this parameter.

Details

The PC algorithm as proposed by Spirtes et al. (2000) is implemented. The variables must be either continuous or categorical, only. The skeleton of the PC algorithm is order independent, since we are using the third heuristic (Spirte et al., 2000, pg. 90). At every stage of the algorithm use the pairs which are least statistically associated. The conditioning set consists of variables which are most statistically associated with each other of the pair of variables.

For example, for the pair (X, Y) there can be two conditioning sets for example (Z1, Z2) and (W1, W2). All p-values and test statistics and degrees of freedom have been computed at the first step of the algorithm. Take the p-values between (Z1, Z2) and (X, Y) and between (Z1, Z2) and (X, Y). The conditioning set with the minimum p-value is used first. If the minimum p-values are the same, use the second lowest p-value. If the unlikely, but not impossible, event of all p-values being the same, the test statistic divided by the degrees of freedom is used as a means of choosing which conditioning set is to be used first.

If two or more p-values are below the machine epsilon (.Machine$double.eps which is equal to 2.220446e-16), all of them are set to 0. To make the comparison or the ordering feasible we use the logarithm of p-value. Hence, the logarithm of the p-values is always calculated and used.

In the case of the G2G^2 test of independence (for categorical data) with no permutations, we have incorporated a rule of thumb. If the number of samples is at least 5 times the number of the parameters to be estimated, the test is performed, otherwise, independence is not rejected according to Tsamardinos et al. (2006). We have modified it so that it calculates the p-value using permutations.

Value

A list including:

stat

The test statistics of the univariate associations.

ini.pvalue

The initial p-values univariate associations.

pvalue

The logarithm of the p-values of the univariate associations.

runtime

The amount of time it took to run the algorithm.

kappa

The maximum value of k, the maximum cardinality of the conditioning set at which the algorithm stopped.

n.tests

The number of tests conducted during each k.

G

The adjancency matrix. A value of 1 in G[i, j] appears in G[j, i] also, indicating that i and j have an edge between them.

sepset

A list with the separating sets for every value of k.

Author(s)

Marios Dimitriadis.

R implementation and documentation: Marios Dimitriadis <[email protected]>.

References

Spirtes P., Glymour C. and Scheines R. (2001). Causation, Prediction, and Search. The MIT Press, Cambridge, MA, USA, 3nd edition.

Tsamardinos I., Borboudakis G. (2010) Permutation Testing Improves Bayesian Network Learning. In Machine Learning and Knowledge Discovery in Databases. ECML PKDD 2010. 322-337.

Tsamardinos I., Brown E.L. and Aliferis F.C. (2006). The max-min hill-climbing Bayesian network structure learning algorithm. Machine learning 65(1):31-78.

See Also

g2Test, g2Test_univariate, cora, correls

Examples

# simulate a dataset with continuous data
dataset <- matrix(rnorm(100 * 50, 1, 100), nrow = 100) 
a <- pc.skel(dataset, method = "pearson", alpha = 0.05)

Skewness and kurtosis coefficients

Description

Skewness and kurtosis coefficients.

Usage

skew(x, pvalue = FALSE)

kurt(x, pvalue = FALSE)

Arguments

x

A numerical vector with data.

pvalue

If you want a hypothesis test that the skewness or kurtosis are significant set this to TRUE. This checks whether the skewness is significantly different from 0 and whether the kurtosis is significantly different from 3.

Details

The sample skewness and kurtosis coefficient are calculated. For the kurtosis we do not subtract 3.

Value

If "pvalue" is FALSE (default value) the skewness or kurtosis coefficients are returned. Otherwise, the p-value of the significance of the coefficient is returned.

Author(s)

Klio Lakiotaki

R implementation and documentation: Klio Lakiotaki <[email protected]>.

References

https://en.wikipedia.org/wiki/Skewness

https://en.wikipedia.org/wiki/Kurtosis

See Also

colskewness, skew.test2, colmeans, colVars, colMedians

Examples

x <- rgamma(500,1, 4)
res<-skew(x)
res<-kurt(x, TRUE)

Some summary statistics of a vector for each level of a grouping variable.

Description

Some summary statistics of a vector for each level of a grouping variable.

Usage

group(x,ina,method="sum",ina.min=NULL,ina.max = NULL,
	ina.length.unique=NULL,mad.method="median")
group.sum(x, ina,ina.max = NULL,ina.min = NULL)

Arguments

x

A numerical vector with data.

ina

A numerical vector with numbers. Note that zero and negative values are not allowed as this can cause R to run forever or crash.

ina.length.unique

Length of the unique numerical values of ina argument.

method

A character vector with values "sum", "var", "all", "any", "mad", "mean", "med", "min", "max", "min.max".

ina.max

Maximum number for vector ina.

ina.min

Minimum number for vector ina.

mad.method

A character vector with values "median", for median absolute deviation or "mean", for mean absolute deviation. This works only with method="mad".

Details

This command works only for vectors. Median absolute deviation, mean, median, minimum, maximum are some of the options offered.

Value

A vector with the variance, or standard deviation, or mean, or minimum, or maximum, or median, or minimum-maximum of x for each distinct value of ina.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Manos Papadakis <[email protected]> and Michail Tsagris <[email protected]>.

See Also

colmeans, colVars, colMedians

Examples

x <- rgamma(100,1, 4)
ina <- sample(1:5, 100, TRUE)
res<-group(x, ina,method="var")

Sort - Integer Sort - Sort a vector coresponding to another

Description

Fast sorting a vector.

Usage

Sort(x,descending=FALSE,partial=NULL,stable=FALSE,na.last=NULL,parallel = FALSE)
Sort.int(x)
sort_cor_vectors(x, base, stable = FALSE, descending = FALSE)

Arguments

x

A numerical/integer/character vector with data.

base

A numerical/character vector to help sorting the x.

descending

A boolean value (TRUE/FALSE) for sorting the vector in descending order. By default sorts the vector in ascending.

partial

This argument has two usages. The first is an index number for sorting partial the vector. The second is a vector with 2 values, start and end c(start,end). Gives you a vector where the elements between start and end will be sorted only. Not character vector.

stable

A boolean value (TRUE/FALSE) for choosing a stable sort algorithm. Stable means that discriminates on the same elements. Not character vector.

na.last

Accept 4 values. TRUE, FALSE, NA, NULL.

TRUE/FALSE: for put NAs last or first.

NA: for remove NAs completely from vector.

NULL: by default. Leave it like that if there is no NA values.

parallel

Do you want to do it in parallel, in C++? TRUE or FALSE. (Supported on Windows and most of the unix)

Details

This function uses the sorting algorithm from C++. The implementation is very fast and highly optimised. Especially for large data.

Value

Sort and Sort.int: The sorted vector.

sort_cor_vectors: The first argument but sorted acording to the second.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

nth, colnth, rownth,sort_unique, Round

Examples

x <- rnorm(1000)
s1 <- Sort(x)
s2 <- sort(x)
all.equal(s1,s2) #true  but not if many duplicates.

s1 <- Sort(x,partial=100)
s2 <- sort(x,partial=100)
all.equal(s1,s2) #true


s1 <- Sort(x,stable=TRUE)
s2 <- sort(x)
all.equal(s1,s2) #true

x <- as.character(x)
s1 <- Sort(x)
s2 <- sort(x)
all.equal(s1,s2) #true

y <- runif(1000)
b <- sort_cor_vectors(x,y)

x<-rpois(100,100)
all.equal(Sort.int(x),sort.int(x))

x<-y<-y<-s1<-s2<-NULL

Sorting of the columns-rows of a matrix

Description

Fast sorting of the columns-rows of a matrix.

Usage

colSort(x, descending = FALSE, stable = FALSE, parallel=FALSE, cores = 0)
rowSort(x, descending = FALSE, stable = FALSE, parallel=FALSE, cores = 0)
sort_mat(x,by.row=FALSE,descending=FALSE,stable=FALSE,parallel=FALSE)

Arguments

x

A numerical matrix or data.frame with data.

descending

If you want the sorting in descending order, set this to TRUE.

stable

If you the stable version, so that the results are the same as R's (in the case of ties) set this to TRUE. If this is TRUE, the algorithm is a bit slower.

parallel

Do you want to do it in parallel in C++? TRUE or FALSE. Works with every other argument.

by.row

TRUE or FALSE for applying sort in rows or column.

cores

Number of cores to use for parallelism. Valid only when argument parallel is set to TRUE. Default value is 0 and it means the maximum supported cores.

Value

The matrix with its columns-rows (or rows) independently sorted.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

nth, colMaxs, colMins, colrange, sort_cor_vectors, sort_unique

Examples

x <- matrix( rnorm(100 * 200), ncol = 200 )
s1 <- colSort(x)
#s2 <- apply(x, 2, sort)
#all.equal(as.vector(s1), as.vector(s2))

x<-NULL

Source many R files

Description

Source many R/Rd files.

Usage

sourceR(path,local=FALSE,encode = "UTF-8",print.errors=FALSE)
sourceRd(path,print.errors=FALSE)

Arguments

path

An full path to the directory where R file are.

local

TRUE, FALSE or an environment, determining where the parsed expressions are evaluated. FALSE (the default) corresponds to the user's workspace (the global environment) and TRUE to the environment from which source is called.

encode

Character vector. The encoding(s) to be assumed when file is a character string: see file. A possible value is "unknown" when the encoding is guessed: see the "Encodings" section.

print.errors

A boolean value (TRUE/FALSE) for printing the errors, if exists, for every file.

Details

Reads many R files and source them.

Value

Returns the files that had produced errors during source.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

read.directory, AddToNamespace

Examples

# for example: path="C:\some_file\R\" where is R files are
# system.time( a<-sourceR(path) )
# for example: path="C:\some_file\man\" where is Rd files are
# system.time( a<-sourceRd(path) )

Spatial median for Euclidean data

Description

Spatial median for Euclidean data.

Usage

spat.med(x, tol = 1e-09)

Arguments

x

A matrix with Euclidean data, continuous variables.

tol

A tolerance level to terminate the process. This is set to 1e-09 by default.

Details

The spatial median, using a fixed point iterative algorithm, for Euclidean data is calculated. It is a robust location estimate.

Value

A vector with the spatial median.

Author(s)

Manos Papadakis and Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Jyrki Mottonen, Klaus Nordhausen and Hannu Oja (2010). Asymptotic theory of the spatial median. In Nonparametrics and Robustness in Modern Statistical Inference and Time Series Analysis: A Festschrift in honor of Professor Jana Jureckova.

T. Karkkaminen and S. Ayramo (2005). On computation of spatial median for robust data mining. Evolutionary and Deterministic Methods for Design, Optimization and Control with Applications to Industrial and Societal Problems, EUROGEN 2005, R. Schilling, W.Haase, J. Periaux, H. Baier, G. Bugeda (Eds) FLM, Munich. http://users.jyu.fi/~samiayr/pdf/ayramo_eurogen05.pdf

See Also

colMedians

Examples

res<-spat.med( as.matrix( iris[, 1:4] ) )
res<-colMeans( as.matrix(iris[, 1:4]) )
res<-colMedians( as.matrix(iris[, 1:4]) )

Spatial median regression

Description

Spatial median regression with Euclidean data.

Usage

spatmed.reg(y, x, tol = 1e-07)

Arguments

y

A matrix with the response variable.

x

The predictor variable(s), they have to be continuous.

tol

The threshold upon which to stop the iterations of the Newton-Rapshon algorithm.

Details

The objective function is the minimization of the sum of the absolute residuals. It is the multivariate generalisation of the median regression.

Value

A list including:

iters

The number of iterations that were required.

be

The beta coefficients.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Biman Chakraborty (2003) On multivariate quantile regression. Journal of Statistical Planning and Inference http://www.stat.nus.edu.sg/export/sites/dsap/research/documents/tr01_2000.pdf

See Also

spat.med, sscov, lmfit

Examples

x <- as.matrix(iris[, 3:4])
y <- as.matrix(iris[, 1:2])
mod1 <- spatmed.reg(y, x)

Spatial sign covariance matrix

Description

Spatial sign covariance matrix.

Usage

sscov(x, me = NULL, tol = 1e-09)

Arguments

x

A matrix with continuous data.

me

If you have already computed the spatial median plug it in here.

tol

A tolerance level to terminate the process of finding the spatial median. This is set to 1e-09 by default.

Details

The spatial median is at first computed (if not supplied) and then the covariance matrix.

Value

The spatial sign covariance matrix.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>.

References

Durre A, Vogel D. and D.E. Tyler D.E.(2014). The spatial sign covariance matrix with unknown location. Journal of Multivariate Analysis, 130: 107-117. http://arxiv.org/pdf/1307.5706v2.pdf

See Also

spat.med, spatmed.reg

Examples

res<-sscov( as.matrix(iris[, 1:4]) )

Fast calculation of the spherical and hyperspherical median

Description

It calculates, very fast, the (hyper-)spherical median of a sample.

Usage

mediandir(x)

Arguments

x

The data, a numeric matrix with unit vectors.

Details

The "mediandir" employes a fixed poit iterative algorithm stemming from the first derivative (Cabrera and Watson, 1990) to find the median direction as described in Fisher (1985) and Fisher, Lewis and Embleton (1987).

Value

The median direction.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Fisher N. I. (1985). Spherical medians. Journal of the Royal Statistical Society. Series B, 47(2): 342-348.

Fisher N. I., Lewis T. and Embleton B. J. (1987). Statistical analysis of spherical data. Cambridge university press.

Cabrera J. and Watson G. S. (1990). On a spherical median related distribution. Communications in Statistics-Theory and Methods, 19(6): 1973-1986.

See Also

vmf.mle

Examples

m <- rnorm(3)
m <- m / sqrt( sum(m^2) )
x <- rvmf(100, m, 10)
res<-mediandir(x)
x <- NULL

Standardisation

Description

Standardisation.

Usage

standardise(x, center = TRUE, scale = TRUE)

Arguments

x

A matrix with data. It has to be matrix, if it is data.frame for example the function does not turn it into a matrix.

center

Should the data be centred as well? TRUE or FALSE.

scale

Should the columns have unit variance, yes (TRUE) or no (FALSE)?

Details

Similar to R's built in functions "scale" there is the option for centering or scaling only or both (default).

Value

A matrix with the standardised data.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colVars, colmeans, colMads

Examples

x <- matrnorm( 100, 100 )
a1 <- scale(x)[1:100, ] 
a2 <- standardise(x) 
all.equal(as.vector(a1), as.vector(a2))
x <- NULL

Sub-matrix

Description

Sub-matrix.

Usage

submatrix(x,rowStart=1,rowEnd=1,colStart=1,colEnd=1)

Arguments

x

A Matrix, List, Dataframe or Vector.

rowStart

Start of the row.

rowEnd

End of the row.

colStart

Start of the col.

colEnd

End of the col.

Value

sub matrix like R's, x[startrow:endrow,startcol:endcol]. Fast especially for big sub matrices.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

Match, mvbetas, correls, univglms, colsums, colVars

Examples

x <- matrix( rnorm(100 * 100), ncol = 100 )
res<-submatrix(x,1,50,1,25) # x[1:50,1:25]

x<-NULL

Table Creation - Frequency of each value

Description

Table Creation - Frequency of each value.

Usage

Table(x,y=NULL,names = TRUE,useNA = FALSE,rm.zeros = FALSE)
Table.sign(x,names = TRUE,useNA = FALSE)

Arguments

x

A vector with numeric/character data.

names

A logical value (TRUE/FALSE) for add names.

y

A vector with numeric/character data. Doesn't work with "useNA".

rm.zeros

A logical value for removing zero columns/rows. Only for integer vectors for now.

useNA

Table: Integer/logical value:

FALSE: not NA values in vector. TRUE: count NAs and add the value in the last position of the returned vector. any other integer except 0,1: for just removing NAs.

Table.sign: Logical value, TRUE, for count NAs. Otherwise FALSE.

Doesn't work character data.

Details

Like R's "table":

for giving one argument,"x": If "names" is FALSE then, if "useNA" is TRUE then the NAs will be count, if is FALSE it means there are no NAs and for any other integer value the NAs will be ignored.

for giving two arguments,"x","y": If "names" is FALSE then, creates the contigency table, otherwise sets the col-row names with discrete values. If "rm.zeros" is FALSE then it won't remove the zero columns/rows from the result but it will work only for positive integers for now. For this if "names" is TRUE then the col-row names will be the seq(min(),max()) for "x","y". In future updates it will be changed.

for both algorithms: You can't use "useNA" with "names" for now. It is much faster to get the result without names (names = FALSE) but all the algorithms are more efficient than R's.

Like R's "table(sign())" but more efficient. Count the frequencies of positives, negatives, zeros and NAs values. If argument "names" is FALSE then the returned vector doesn't have names. Otherwise "-1,0,+1,NA". If "useNA" is TRUE then the NAs will be count, otherwise not. You can use "useNA" with "names".

Value

Table:

for giving one argument,"x": if "names" is TRUE then return a vector with names the discrete values of "x" and values there frequencies, otherwise only the frequencies

for giving two arguments,"x","y": if "names" is TRUE then return a contigency matrix with rownames the discrete values of "x", colnames the dicrete values of "y" and values the freuquencies of the pairs, otherwise only the freuquencies of the pairs.

Table.sign: A vector with 4 values/frequencies: index 1: negatives index 2: zeros index 3: postives if "names" is TRUE then the returned vector have names "-1,0,+1". if "useNA" is TRUE then 4th value has the frequencies of NAs and the returned vector will have one more name, "-1,0,+1,NA", if "names" is also TRUE.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans, read.directory, is_integer, as_integer

Examples

x<-runif(10)
y1<-Table(x)
y2<-as.vector(table(x)) # Neads a lot of time.
all.equal(y1,y2)
y1<-Table(x,names=FALSE)
all.equal(y1,y2) # the name attribute of y1 is null 

y1<-Table.sign(x)
y2<-table(sign(x))
all.equal(y1,y2)

x<-y1<-y2<-NULL

Tests for the dispersion parameter in Poisson distribution

Description

Tests for the dispersion parameter in Poisson distribution.

Usage

poisdisp.test(y, alternative = "either", logged = FALSE)
pois.test(y, logged = FALSE)

Arguments

y

A numerical vector with count data, 0, 1,...

alternative

Do you want to test specifically for either over or underspirsion ("either"), overdispersion ("over") or undersispersion ("under")?

logged

Set to TRUE if you want the logarithm of the p-value.

Value

A vector with two elements, the test statistic and the (logged) p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

References

Yang Zhao, James W. Hardin, and Cheryl L. Addy. (2009). A score test for overdispersion in Poisson regression based on the generalized Poisson-2 model. Journal of statistical planning and inference 139(4): 1514-1521.

Dimitris Karlis and Evdokia Xekalaki (2000). A Simulation Comparison of Several Procedures for Testing the Poisson Assumption. Journal of the Royal Statistical Society. Series D (The Statistician), 49(3): 355-382.

Bohning, D., Dietz, E., Schaub, R., Schlattmann, P. and Lindsay, B. (1994) The distribution of the likelihood ratio for mixtures of densities from the one-parameter exponential family. Annals of the Institute of Statistical Mathematics, 46(): 373-388.

See Also

poisson.mle, negbin.mle, poisson.anova, poisson.anovas, poisson_only

Examples

y <- rnbinom(500, 10, 0.6)
res<-poisdisp.test(y, "either")
res<-poisdisp.test(y, "over")
res<-pois.test(y)

y <- rpois(500, 10)
res<-poisdisp.test(y, "either")
res<-poisdisp.test(y, "over")
res<-pois.test(y)

Topological sort of a DAG

Description

Topological sort of a DAG.

Usage

topological_sort(dag)

Arguments

dag

A square matrix representing a directed graph which contains 0s and 1s. If G[i, j] = 1 it means there is an arrow from node i to node j. When there is no edge between nodes i and j if G[i, j] = 0.

Details

The function is an R translation from an old matlab code.

Value

A vector with numbers indicating the sorting. If the dag is not a Directed acyclic Graph, NA will be returned.

Author(s)

Michail Tsagris and Manos Papadakis

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>

References

Chickering, D.M. (1995). A transformational characterization of equivalent Bayesian network structures. Proceedings of the 11th Conference on Uncertainty in Artificial Intelligence, Montreal, Canada, 87-98.

See Also

floyd, pc.skel

Examples

G <- matrix(0, 5, 5)
G[2, 1] <- 1
G[3, 1] <- 1
G[4, 2] <- 1
G[5, 4] <- 1
res<-topological_sort(G)
G[2, 4] <- 1
res<-topological_sort(G)

Transpose of a matrix

Description

Transpose of a matrix.

Usage

transpose(x)

Arguments

x

A numerical square matrix with data.

Value

The transposed matrix.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[email protected]>.

References

Gilbert Strang (2006). Linear Algebra and its Applications (4th edition).

See Also

nth, colMaxs, colMins, colrange

Examples

x <- matrix( rnorm(100 * 100), ncol = 100, nrow=100 )
transpose(x) #t(x)

x<-NULL

Uniformity tests for circular data

Description

Hypothesis tests of uniformity for circular data.

Usage

kuiper(u)

watson(u)

Arguments

u

A numeric vector containing the circular data which are expressed in radians.

Details

These tests are used to test the hypothesis that the data come from a circular uniform distribution.

Value

A vector with two elements, the value of the test statistic and its associated p-value.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Jammalamadaka, S. Rao and SenGupta, A. (2001). Topics in Circular Statistics, pg. 153-55 (Kuiper's test) & 156-157 (Watson's test).

See Also

vmf.mle, rvonmises

Examples

x <- rvonmises(n = 50, m = 2, k = 10)
res<-kuiper(x)
res<-watson(x)
x <- runif(50, 0, 2 * pi)
res<-kuiper(x)
res<-watson(x)

Variance (and standard deviation) of a vector

Description

Variance (and standard deviation) of a vector.

Usage

Var(x, std = FALSE,na.rm = FALSE)

Arguments

x

A vector with data.

std

If you want the standard deviation set this to TRUE, otherwise leave it FALSE.

na.rm

TRUE or FAlSE for remove NAs if exists.

Details

This is a faster calculation of the usual variance of a matrix.

Value

The variance of the vector.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]> and Manos Papadakis <[email protected]>.

See Also

colVars, cova

Examples

x <- rnorm(100)
a1 <- Var(x)
a2 <- var(x)
x<-NULL

Vector allocation in a symmetric matrix

Description

Vector allocation in a symmetric matrix.

Usage

squareform(x)

Arguments

x

An numverical vector whose size must be the one that matches the dimensions of the final matrix. See examples.

Details

The functions is written in C++ in order to be as fast as possible.

Value

A symmetric matrix. The vector is allocated in the upper and in the lower part of the matrix. The diagonal is filled with zeros.

Author(s)

R implementation and documentation: Manos Papadakis <[email protected]>.

See Also

colShuffle, colVars, colmeans

Examples

x <- rnorm(1)
res<-squareform(x)  ## OK
x <- rnorm(3)
res<-squareform(x)  ## OK
x <- rnorm(4)
res<-squareform(x)  ## not OK

Weibull regression model

Description

Weibull regression model.

Usage

weib.reg(y, x, tol = 1e-07, maxiters = 100)

Arguments

y

The dependent variable; a numerical vector with strictly positive data, i.e. greater than zero.

x

A matrix with the data, where the rows denote the samples (and the two groups) and the columns are the variables. This can be a matrix or a data.frame (with factors).

tol

The tolerance value to terminate the Newton-Raphson algorithm.

maxiters

The max number of iterations that can take place in each regression.

Details

The function is written in C++ and this is why it is very fast. No standard errors are returned as they are not corectly estimated. We focused on speed.

Value

When full is FALSE a list including:

iters

The iterations required by the Newton-Raphson.

loglik

The log-likelihood of the model.

shape

The shape parameter of the Weibull regression.

be

The regression coefficients.

Author(s)

Stefanos Fafalios

R implementation and documentation: Stefanos Fafalios <[email protected]>.

References

McCullagh, Peter, and John A. Nelder. Generalized linear models. CRC press, USA, 2nd edition, 1989.

See Also

poisson_only, logistic_only, univglms, regression

Examples

x <- matrix(rnorm(100 * 2), ncol = 2)
y <- rexp(100, 1)
res<-weib.reg(y, x)

Yule's Y (coefficient of colligation)

Description

Yule's Y (coefficient of colligation).

Usage

yule(x)

Arguments

x

A 2 x 2 matrix or a vector with 4 elements. In the case of the vector make sure it corresponds to the correct table.

Details

Yule's coefficient of colligation is calculated.

Value

Yule's Y is returned.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <[email protected]>

References

Yule G. Udny (1912). On the Methods of Measuring Association Between Two Attributes. Journal of the Royal Statistical Society, 75(6):579-652.

See Also

col.yule, odds.ratio

Examples

x <- rpois(4, 30) + 2
res<-yule(x)
res<-yule( matrix(x, ncol = 2) )