> On 27 Sep 2015, at 22:12 , Bert Gunter <bgunter.4...@gmail.com> wrote: > >> >> Due to missing data, R originally classified each X and Y variable as a >> ‘factor’, subsequently changed to ‘numeric’ via ‘as.numeric’ command. > > No. > a) missing data will not cause numeric data to become factor. There's > something wrong in the data from the beginning (as Thierry said)
Well, if you forget to tell R what the input code for missing is (na.strings if you use read.table), then that is de facto what happens: The whole column gets interpreted as character and subsequently converted to a factor. The fix is to _remember_ to tell R what missing value codes are being used. > > b) If f is numeric data that is a factor, as.numeric(f) is almost > certainly **not** the corrrect way to change it to numeric. Amen... as.numeric(as.character(f)) if you must, but the proper fix is usually the above. -pd -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
