Hello everyone, Sorry if my question is not clear, my first language is not English, but Portuguese.
I am building a model for my data, using non-binomial error. I am having a bit of a problem when updating the model to remove parameters that I no do no autocorrelate with other variables (I have used a autocorrelation function for this). So my first model looks like this: model1.glm.nb<-glm.nb(ozone ~ ., data=climate.dat) summary(model1.glm.nb) model1AIC.glm.nb<-stepAIC(model1.glm.nb) When I run it, it doesn't give me any significance. So I run a second model, with my autocorrelation table, and remove one more variable that does not autocorrelate with other (anything below .07) model2.glm.nb2 <- update(model1.glm.nb, ~ . - rain, data=climate.dat) summary(model2.glm.nb2) Now, when I run a 3rd. model to remove rain, it shows after summary that rain has been removed. Once I do a forth model rain is again in it. How can I remove more than one variable in one go? I was thinking doing something like this: model2.glm.nb2 <-update(model1.glm.nb, ~ . -rain, -temp, data=climate.dat) summary(model2.glm.nb2) Obviously using the - sign is not working and I am getting an error message. Thank you for your help. Michelle [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.