Given the size of my dataframe (>400 columns, >35000 rows), I should have clarified that speed and efficiency is perhaps as important as "elegance", and I'd like to use the examples to learn about any corrections and improvements I can make in the examples I provided. Thanks for any help you can offer. (I am using R x64 2.15.2 on Windows 7.)
On Wed, Jun 26, 2013 at 3:14 PM, Anika Masters <anika.mast...@gmail.com> wrote: > I want to "paste" the contents of the first column of a dataframe > with all the columns of the same dataframe. > > > > What is a "good" way to do this, perhaps something more elegant than > what I have below. (My actual dataframe has ~400 columns and ~35000 > rows.) > > > > example1: > > mydf <- data.frame( matrix(data=1:15, nrow=5, ncol=3) ) > > mydf2 <- mydf > > temp2 <- paste(unlist(mydf[,1]) , unlist(mydf), sep="_") > > mydf2[ ,] <- temp2 > > > > example2: > > mydf2 <- mydf > > > > for(i in 1:ncol(mydf2) ) { > > mydf2[i] <- paste( mydf[,1], mydf[ ,i], sep='_') > > } ______________________________________________ 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.