Dear R-people, I would like to construct a model frame while keeping eventual NA-s in it. The code looks like in lm():
m <- match(c("formula", "data", "subset", "weights", "na.action", "offset"), names(mf), 0) mfO <- mf[c(1, m)] mfO$drop.unused.levels <- TRUE mfO[[1]] <- as.name("model.frame") names(mfO)[2] <- "formula" mfO <- eval(mfO, parent.frame()) The problem is that eval() removes all the observation which include NA-s. Are there ways to get the frames and keep NA-s? I see, I can play around with the "na.action" attribute of the resulting frame, but how can I set the na.action? Thanks in advance, Ott ______________________________________________ R-help@stat.math.ethz.ch 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.