I'm sure there are more efficient ways, but this works: > test1 <- matrix(runif(50), nrow=10, ncol=5) > ## test1 <- as.data.frame(test1) > test1 <- rbind(test1, NA) > test1[11, c(1,3)] <- colSums(test1[1:10,c(1,3)]) > test1
HTH, Bill. William Michels, Ph.D. On Fri, Mar 31, 2017 at 9:20 AM, Bruce Ratner PhD <b...@dmstat1.com> wrote: > > Hi R'ers: > Given a data.frame of five columns and ten rows. > I would like to take the sum of, say, the first and third columns only. > For the remaining columns, I do not want any calculations, thus rending their > "values" on the "total" row blank. The sum/total row is to be combined to the > original data.frame, yielding a data.frame with five columns and eleven rows. > > Thanks, in advance. > Bruce > > > ______________ > Bruce Ratner PhD > The Significant Statistician™ > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.