On Mar 28, 2014, at 3:38 PM, Jonathan Greenberg <j...@illinois.edu> wrote:
> R-helpers: > > Hopefully this is an easy one. Given a lookup table: > > mylevels <- data.frame(ID=1:10,code=letters[1:10]) > > And a set of values (note these do not completely cover the mylevels range): > > values <- c(1,2,5,5,10) > > How do I convert values to a factor object, using the mylevels to > define the correct levels (ID matches the values), and code is the > label? > > --j One approach would be to use ?merge and specify the 'by.*' arguments using column indices, where 'values' is column 1 and you want to match that with mylevels$ID, which is also column 1. Hence: > merge(values, mylevels, by.x = 1, by.y = 1) x code 1 1 a 2 2 b 3 5 e 4 5 e 5 10 j Regards, Marc Schwartz ______________________________________________ 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.
