[R] offset and poisson regression

Not sure that the list is the best place for this question, but we are going mad with this... We are trying to fit a poisson regression to count data, eg the number of fledged youngs of blue tits (NPe) as a function of the clutch size (GPc) and other environment variables. Here are the

Re: [R] offset and poisson regression

You should use offset(log(Gpc)) instead of offset(Gpc) options(width = 65) fm - glm(NPe ~ 1 + offset(log(GPc)), family = poisson,data = tab) fitted(fm) 1234678 3.181818 3.818182 3.818182 4.454545 3.181818 3.818182 3.181818 9