If we assume that your data are in a data frame (which doesn't allow spaces in column names, hence the periods in the call below):
>df = data.frame(Major.Gleason = c(4,5,2,3), Minor.Gleason = c(3,2,4,3)) You can paste together the contents of the two columns with a plus sign in between using the paste() function. The sep='' option at the end of the function call specifies that no spaces should be included between pasted items. >output = paste(as.character(df [,'Major.Gleason']), '+', as.character(df[ >,'Minor.Gleason']), sep='') The new object 'output' is a character vector containing the 4 strings you're after: > print(output) [1] "4+3" "5+2" "2+4" "3+3" On Mon, Jun 20, 2011 at 11:31 AM, Ben Ganzfried <ben.ganzfr...@gmail.com> wrote: > > Hi -- > > I had a pretty quick R question since unfortunately I have not been able to > find an answer on Google. It shouldn't take much more than a minute to > answer. > > I'm trying to add up the major gleason grade and minor gleason grade for an > analysis of patients with prostate cancer. One column has values under > "Major Gleason" and another column has values under "Minor Gleason." For > example, > Major Gleason Minor Gleason > 4 3 > 5 2 > 2 4 > 3 3 > > I want my output to be: > "4+3" > "5+2" > "2+4" > "3+3" > > The quasi-pseudocode in Java is basically: > > major = column$majorGleason > minor = column$minorGleason > for item in len(Major Gleason) { > string s = major(item) "+" minor(item); > } > return s; > > But trying the same idea in R: > > string <- major "+" minor > > gives me an error: "unexpected string constant in..." > > I would greatly appreciate any help. > > Thanks, > > Ben > > [[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. -- ___________________________ Luke Miller Postdoctoral Researcher Marine Science Center Northeastern University Nahant, MA (781) 581-7370 x318 ______________________________________________ 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.