Happy new year Zelig people! :) I am trying to use Zelig to simulate from a logit.gam model, however I find that it gives me only expected values of 1, which is not correct I think. The fitted model seems ok, but setx/sim somehow messes up the scaling of the x variable. An example x <- rnorm(1000) y <- (x+rnorm(1000)) > 0 mydata <- data.frame(x=x,y=y) z.out <- zelig(y~s(x),data=mydata,model="logit.gam") x.out <- setx(z.out) s.out <- sim(z.out,x.out) summary(s.out) #this is all nice what you would expect. Now let's rescale x. mydata$x <- mydata$x + 10 z.out <- zelig(y~s(x),data=mydata,model="logit.gam") x.out <- setx(z.out) s.out <- sim(z.out,x.out) summary(s.out) this second model simulates only expected values around 1, although it should be the same model as the first one, but with higher x values, so if no x is specified in setx(), I would expect the same expected values. Why does this happen? I am using R 2.8.0, Zelig 3.4.0 and mgcv_1.4-1.1 Jeroen - Zelig Mailing List, served by Harvard-MIT Data Center Send messages: zelig(a)lists.gking.harvard.edu [un]subscribe Options: http://lists.gking.harvard.edu/?info=zelig Zelig program information: http://gking.harvard.edu/zelig/