Just in case someone else stumbles onto this thread and is facing a similar issue: The quick solution for me turned out to be using Glm and Predict in the rms package. Thanks go to Joshua and Ista for helping me out with this issue. Double thanks go to Joshua for suggesting I take a closer look at the rms package.
library(rms) dat <- data.frame(xxA = rnorm(20,10), xxB = rnorm(20,20)) dat$out <- with(dat,xxA+xxB+xxA*xxB+rnorm(20,20)) rms.res <- Glm(out ~ scale(xxA)*scale(xxB),data=dat) newdata <- as.data.frame(Predict(rms.res,xxA=c(-1,0,1),xxB=c(-1,0,1))[,1:3]) ----------------------------------- Russell S. Pierce, M.A. Visual Cognition Lab Department of Psychology University of California, Riverside 900 University Avenue Riverside, CA 92521 Lab Phone: (951) 827-7399 ______________________________________________ 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.
