PermTest {pgirmess} | R Documentation |
Permutation test for lm, lme and glm (binomial and Poisson) objects
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,...)
obj |
an object of class lm, lme, or glm |
B |
number of permutations, default = 1000 |
... |
used to pass other arguments |
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.
A list object of class PermTest including:
p.value |
the p value obtained |
B |
the number of permutations |
call |
the call |
This generic function is implemented in R language, thus can be quite slow.
Patrick Giraudoux <patrick.giraudoux@univ-fcomte.fr>. The implementation of PermTest.lme has been helped by Renaud Lancelot
library(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=250) library(nlme) fm2 <- lme(distance ~ age + Sex, data = Orthodont, random = ~ 1) PermTest(fm2,B=250)