jdog76 wrote > > I am positive this problem has a very simple solution, but I have been > unable to find it, so I am asking for your help. I need to know how to > look something up in one data frame and add it as a column in another. If > I have a data frame that looks like this: > >> frame1 > ID score test age > 1 Guy1 10 1 20 > 2 Guy1 13 2 20 > 3 Guy2 9 1 33 > 4 Guy2 11 2 33 > > and another frame that looks like this: > >> frame2 > ID > 1 Guy1 > 2 Guy2 > > How do I add a column to frame2 so it looks like this: > > ID age > 1 Guy1 20 > 2 Guy2 33 > > I know this must be simple, but I couldn't find the solution by searching. > > thanks so much > Jeremy >
How about .... frame2$age = frame1[match(frame2$ID, frame1$ID),"age"] print(frame2) ID age 1 Guy1 20 2 Guy2 33 HTH Pete -- View this message in context: http://r.789695.n4.nabble.com/add-column-with-values-found-in-another-data-frame-tp4295626p4296307.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.