Thanks !! This aggregate function is really powerful to do this kind of manipulation! Looks like R is quite versatile for text manipulation, I don't need to learn Perl language.
Appreciate all your guys help! WONG, Hon-Kit (Stephen) Cleary Lab, Dept of Pathology Stanford University Lokey Stem Cell Research Building, Room G2035 259 Campus Drive Stanford, CA 94305 -----Original Message----- From: Dennis Murphy [mailto:djmu...@gmail.com] Sent: Friday, May 13, 2011 8:05 PM To: wong, honkit (Stephen) Cc: r-help@r-project.org Subject: Re: [R] Adding same items together in data.frame Hi: There are many ways to do this sort of thing in R; one way is (naming your example data frame d) aggregate(value ~ gene, data = d, FUN = sum) gene value 1 aa 74 2 bb 10 3 cc 9 4 dd 100 5 ee 55 This code line works for R-2.11.0 and later. HTH, Dennis On Fri, May 13, 2011 at 4:06 PM, wong, honkit (Stephen) <hon...@stanford.edu> wrote: > Dear All, > I am new to R. I have a 2 column data frame with more than ten > thousand rows. Something like below. I want to add up all duplicated > items, e.g. the three "aa" add up together to get a single value > gene=a, value=74. How can I do that?? Thanks for help ! gene value > aa 20 > bb 10 > cc 9 > aa 30 > aa 24 > dd 100 > ee 55 > .... ... > Millions thanks. > Best Regards, > hon > > WONG, Hon-Kit (Stephen) > Cleary Lab, Dept of Pathology > Stanford University > > ______________________________________________ > 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. > ______________________________________________ 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.
