You did not show what answer you expected, but does the following do what you want?
> match(sc$TERM, TermList) [1] 11 20 30 Making a factor whose levels are TermList may also be useful. (The exclude=NULL is to factor doesn't drop NA from the levels). > sc$fTERM <- factor(sc$fTERM, levels=TermList, exclude=NULL) > str(sc) 'data.frame': 3 obs. of 2 variables: $ TERM : Factor w/ 3 levels "200208","200701",..: 1 2 3 $ fTERM: Factor w/ 33 levels NA,"199801","199808",..: 11 20 30 Bill Dunlap TIBCO Software wdunlap tibco.com On Thu, Jan 22, 2015 at 8:01 AM, Charles Stangor <cstan...@gmail.com> wrote: > Hi, > > Is there a way to easily convert the list of course terms into sequential > integers in the dataframe (see code below)? > > eg. "199801" = 1; "199808"=2 > > I know I can use recode but shouldn't "which" work? > > Thanks in advance! > > > sc = data.frame(c("200208", "200701", "201201")) > names(sc) = c("TERM") > > TermList = c(NA, "199801", "199808", "199901", "199908", "200001", > "200008", "200101", "200108", > "200201", "200208", "200301", "200308", "200401", "200408", > "200501", "200508", > "200601", "200608", "200701", "200708", "200801", "200808", > "200901", "200908", > "201001", "201008", "201101", "201108", "201201", "201308", > "201401", "201408") > > which(TermList==sc$TERM) > > [[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. > [[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.