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...has been run and we have the lm object. And we have a dataframe that has columns that don't correspond by name to the original regressors. I very! naively assumed that doing this (below) would work. It does not. # does not work lm.yx$coefficients<-c("Intercept", "n.x1") dum2<-data.frame(Int=rep(1,200), n.x1=rnorm(200)) predict(lm.yx, newdata=dum2) I know that a simple alternative is to do: # because we messed around with the lm object above, re-building lm.yx<-lm(y~x1) # change names of dum2 to match names of coefficients of lm.yx names(dum2)<-names(coeffic...

I am not sure if this question has been asked before - but is there a procedure in R (in lm or glm?) that is equivalent to ENTER and REMOVE regression commands in SPSS? Thanks a lot! -- Dimitri Liakhovitski Ninah.com Dimitri.Liakhovitski at ninah.com

Hi, I'm trying to create a linear model for a dataset that has a breakpoint e.g. # dummy dataset x <- 1:20 y <- c(1:10,seq(10.5,15,0.5)) plot(x,y) I've modelled this using the following formula: temp <- lm(y ~ x*(x<=10)+x*(x>10)) I want to be able to omit the intercept (i.e. force the line through zero) from the first of these segments (x<=10) so that I'm only