2 problems : test seems to be a data frame or list with one variable. So you have to specify : as.numeric(test$classcol)
But this will make the internal factor levels the real values, not the numbers you specified. What you need, is as.numeric(as.character(test$classcol)) Cheers Joris On Mon, Oct 19, 2009 at 3:07 PM, John <josip.2...@gmail.com> wrote: > Hello, > > I figure this is quite a simple problem really, but since I'm quite > new to R I need to ask: > > If I have a data frame: > > str(test) : > $ classcol: Factor w/ 3 levels "1","2","3" > > How do I convert the entries in this column to numbers. I.e., I want > to be abl to do simple calculations like test[1,the_column] - test > [2,the_column] without errors. > > > as.numeric(test) yeilds the error "object cannot be coerced to type > 'double'" > > > Thanks! > John > > ______________________________________________ > 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. > ______________________________________________ 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.