[R] multiple comparison of means with glm model

[Wade Wall]

Hi all,

I have a data set that I am analyzing and I am trying to do a multiple
comparison of means under a glm model.  The factors are 2 light
treatments and 3 temperature treatments in a complete block design
analyzed using a glm.

My question is how do I do a multiple comparison of means using the
multcomp() package.  I have used the following code to look at each
treatment separately.

germ.glht<-glht(germ.glm,linfct=mcp(Light="Tukey"))

but would like to add both temp and light.  Is this possible, or is
better to simply set up contrasts and adjust?

Any help would be appreciated.

Wade