PermTest: Permutation test for lm, lme and glm (binomial and Poisson)...

PermTestR Documentation

Permutation test for lm, lme and glm (binomial and Poisson) objects

Description

Permutation test for lm, lme and glm (binomial and Poisson) objects

Usage

    PermTest(obj, B=1000,...)

    ## S3 method for class 'lm'
PermTest(obj, B=1000,...)
    ## S3 method for class 'lme'
PermTest(obj, B=1000,...)
    ## S3 method for class 'glm'
PermTest(obj, B=1000,...)

Arguments

obj

an object of class lm, lme, or glm

B

number of permutations, default = 1000

...

used to pass other arguments

Details

For glm, when the response is a two-column matrix with the columns giving the numbers of successes and failures, PermTest.glm uses permcont(); PermTest.lme requires the library nlme.

Value

A list object of class PermTest including:

p.value

the p value obtained

B

the number of permutations

call

the call

Warning

This generic function is implemented in R language, thus can be quite slow.

Note

The implementation of PermTest.lme has been helped by Renaud Lancelot

Examples


if(require(MASS)){
mylm<-lm(Postwt~Prewt,data=anorexia)
PermTest(mylm,B=250)


## Dobson (1990) Page 93: Randomized Controlled Trial :
    counts <- c(18,17,15,20,10,20,25,13,12)
    outcome <- gl(3,1,9)
    treatment <- gl(3,3)
    glm.D93 <- glm(counts ~ outcome + treatment, family=poisson)
    PermTest(glm.D93,B=100)
    }

if(require(nlme)){
fm2 <- lme(distance ~ age + Sex, data = Orthodont, random = ~ 1)
PermTest(fm2,B=100)
}

  

pgirmess documentation built on May 29, 2024, 4:26 a.m.

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