Hi Or perhaps aggregate
> aggregate(x$F, list(C1=x$C1, C2=x$C2), sum) C1 C2 x 1 1 2 0.5 2 2 2 0.5 Regards Petr On 23 Mar 2007 at 16:13, jim holtman wrote: Date sent: Fri, 23 Mar 2007 16:13:30 -0400 From: "jim holtman" <[EMAIL PROTECTED]> To: "Yuan, Qiaoping (NIH/NIAAA) [E]" <[EMAIL PROTECTED]> Copies to: r-help@stat.math.ethz.ch Subject: Re: [R] subtotal for same row data > try this: > > > x <- as.data.frame(x) > > x > C1 C2 C3 F > R1 1 2 2 0.3 > R2 2 2 2 0.5 > R3 1 2 1 0.2 > > do.call('rbind',by(x, list(x$C1, x$C2), function(z){z$F <- sum(z$F); > z[1,]})) > C1 C2 C3 F > R1 1 2 2 0.5 > R2 2 2 2 0.5 > > > > > > On 3/23/07, Yuan, Qiaoping (NIH/NIAAA) [E] <[EMAIL PROTECTED]> wrote: > > > Hi, There, > > I would like to subtotal the number in a specified > column for all rows > having the same data for specified columns. The > following is the simple > example: > > > > > x=matrix(c(1,2,2,0.3,2,2,2,0.5,1,2,1,0.2),3,4,byrow=T) > > > rownames(x)=c("R1","R2","R3") > > colnames(x)=c("C1","C2","C3","F") > > > x > C1 C2 C3 F > R1 1 2 2 0.3 > R2 2 2 2 0.5 > R3 1 2 1 0.2 > > I > would like to get the subtotal in column "F" based on same row data in > > column "C1" and "C2". The result should be like > > C1 C2 SumF > > 1 2 0.5 # This is 0.3 + 0.2 from R1 and R3 > 2 2 0.5 > > Is there a > simple way to do this? Any help will be greatly appreciated. > > > Qiaoping Yuan > > ______________________________________________ > > R-help@stat.math.ethz.ch 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. > > > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem you are trying to solve? > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch 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. Petr Pikal [EMAIL PROTECTED] ______________________________________________ R-help@stat.math.ethz.ch 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.