prediction from glm
Hugues Santin-Janin <hsantin-janin <at> gct.org.uk> writes:
I try to fit birds counts over years using glm. I have done (with Estate and year as factors): Model1 <- glm(Females~Estate+Year+offset = log(area)), family = quasipoisson(link = log), na.action = "na.exclude")
..
Pred1 <- predict(Model1, type = "response", na.action = "na.exclude") My question is: How can I obtain predictions for Females in each year that are standardized by averaging over the levels of Estate?
You should use the newdata argument in predict.glm to construct the "should-be" data set. The example on the page ?predict.glm creates budworm-data on the fly, but it's probably easier to understand if you create a separate data frame myfemales first, the do predict(Model1, newdata=myfemales,..) in a separate step. Dieter Menne