I strongly suspect that you do not need to do this. What I think you do need to do is to create a new column (which will be a factor) identifying the climate ("a" or "b"), which can then be used to group climates in plots, used as a covariate in statistical analyses, etc. Moreover, there is probably no need for things to be in order (R is not Excel or SPSS or ...).
You can either use regexp's (e.g. grep -- very powerful but with a hefty learning curve) or because of the simplicity of your ID's, ?substring ; e.g. yourdat$clim_type <- substring(yourdat$ID,1,1) Please do some more tutorials on your own, as these (not regexp's) are fairly basic R features that all users should be aware of. Incidentally, check out the "stringr" package, which is supposed to make string manipulation tasks like this easier (I have not used it though). Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Sun, Jul 3, 2016 at 11:14 AM, lily li <chocol...@gmail.com> wrote: > I have a problem in changing row names in a dataframe in R. The first > column is ID, such as aClim_st02, aClim_st03, aClim_st 05, bClim_st01, > bClim_st02, etc. How to rename the names, so that aClim_ all grouped to > aClim, while bClim_ all grouped to bClim? Thanks for your help. > df > > ID temp precip LW SW > aClim_st02 > aClim_st03 > aClim_st05 > bClim_st01 > bClim_st02 > ... > > [[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.