Your data frame didn't come across legibly, try sending it in plain text using the dput() command.
That said, I'd guess you want something like this: d[is.na(d$a),"a"] <- d[is.na(d$b),"b"] The idea is that is.na(d$a) selects only those rows where column "a" is NA and then moves b values into a for only those rows. Write back with the dput() data frame if this doesn't work. Hope this helps, Michael Weylandt On Fri, Sep 2, 2011 at 3:51 PM, Josh Tewksbury <tewk...@uw.edu> wrote: > Hello, I have a dataframe that looks like this: > > a b NA Honduras China NA NA Sudan Japan NA NA Mexico NA Mexico > I would like to replace the NA values in column b with the non-NA values in > column a. I have tried a number of techniques, (if, ifelse) but I must > have > the logic wrong. > > Thanks > -- > Josh > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.