search for: propalive

...ts won't cope with anything more complicated - we're all biologists not statisticians). I hope someone can help. Here is a typical bit of code I'm currently running so you can see what I'm trying to do: exptime is a covariate and both infstat and status are factors mod<-glm(propalive~exptime+infstat+status+ infstat:status, data=dat) library(contrast) contrast(mod3, a = list(status = levels(dat$status), infstat="control", exptime=8230), b = list(status = levels(dat$status), infstat="infected",exptime=8230)) any help gratefully receiv...