Hi. There must be something about the use of update() which I do not grasp, as the next exercise indicates.
Suppose that obj is an object returned by a call to lm() or glm(). Next, a new variable xf is constructed using the same dataframe used for producing obj. Then obj$data <- cbind(obj$data, xf=xf) new.obj <- update(obj, . ~ . + xf) generates Error in eval(predvars, data, env) : object 'xf' not found Could somebody explain what I got wrong, and how to fix it? Best regards, Adelchi Azzalini ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
