Contrasts for glm models

Dne 24. ?nora 2012 15:53 Scott Chamberlain
<scttchamberlain4 at gmail.com> napsal(a):
Hello,

I have looked at the archives and I still can not figure this out. ?So this code

dat <- data.frame(var1 = as.factor(rep(c("a","b"), each=8)),
? ? ? ? ? var2 = as.factor(rep(c("c","d"), 8)),
? ? ? ? ? response = round(rnorm(16, 10, 4), 0))
mod <- glm(response ~ var1 * var2, data=dat, family=poisson)
anova(mod, test="Chisq")

gives me my glm model with poisson error dist, and main effects tests, but I would like to compare the levels of var2 (c and d) within each level of var1 (a and b). ?What I don't want is just c vs. d for var2 averaged across a and b levels of var1.

I imagine multcomp is the way to go here?

Thanks!
--
Scott Chamberlain

? ? ? ?[[alternative HTML version deleted]]

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Hello,
to me it seems that you ask for nesting:
mod <- glm(response ~ var2 %in% var1, data=dat, family=poisson)
But may be I am wrong.
Best,
Martin Weiser

Contrasts for glm models

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