Dear Group: I am trying to create a model frame from a formula for the model as follows:
formula <- y ~ x1 + x2 + x3 X <- model.frame(form=formula,data=mydata) I have some missing values in some the variables, but I want them to be included in my model frame and to be indicated as "NA". Is there a way to do this? thanks, Ravi. ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
