Re: [R] group by-like statement for 2-row matrix

Luc, Eik, Jorge, thanks to all of you! Nice to see how many different solutions there are for the same problem. :) Best Henning Am 07.04.2009 um 22:25 schrieb Jorge Ivan Velez: > > Dear Hans, > > Try also: > > x <- structure(c(2, 1, 2, 1, 3, 2, 4, 1, 4, 3, 4, 3, 5, 2, 5, 1, 6, > 1), .Dim

Re: [R] group by-like statement for 2-row matrix

Dear Hans, Try also: x <- structure(c(2, 1, 2, 1, 3, 2, 4, 1, 4, 3, 4, 3, 5, 2, 5, 1, 6, 1), .Dim = c(2L, 9L)) tapply(x[2,],x[1,],sum) #2 3 4 5 6 #2 2 7 3 1 HTH, Jorge On Tue, Apr 7, 2009 at 11:06 AM, Hans-Henning Gabriel < hanshenning.gabr...@gmail.com> wrote: > Hi, > > my problem is as foll

Re: [R] group by-like statement for 2-row matrix

briel" Cc: r-help@r-project.org Date: Tue, 07 Apr 2009 17:36:45 +0200 Subject: Re: [R] group by-like statement for 2-row matrix see ?aggregate m<-rbind(sample(2:6,9,replace=T),sample(1:3,9,replace=T)) aggregate(m[2,],by=list(m[1,]),sum) Hans-Henning Gabriel schrieb: > Hi, > > my probl

Re: [R] group by-like statement for 2-row matrix

see ?aggregate m<-rbind(sample(2:6,9,replace=T),sample(1:3,9,replace=T)) aggregate(m[2,],by=list(m[1,]),sum) Hans-Henning Gabriel schrieb: Hi, my problem is as follows: I have a matrix of two rows like this: 2 2 3 4 4 4 5 5 6 1 1 2 1 3 3 2 1 1 Can I apply something like "group by" in sql? W

Re: [R] group by-like statement for 2-row matrix

Hi Henning, Although there might be a better way to do this, I'd suggest (with my.matrix being the matrix you provided): complete.vector = rep(my.matrix[1,],my.matrix[2,]) ; table(complete.vector) ; Is this what you're looking for? Cheers, Luc Hans-Henning Gabriel wrote: Hi, my problem i

[R] group by-like statement for 2-row matrix

Hi, my problem is as follows: I have a matrix of two rows like this: 2 2 3 4 4 4 5 5 6 1 1 2 1 3 3 2 1 1 Can I apply something like "group by" in sql? What I want to achieve is the some of second row for each unique entry of first row: 2 -> 2 (=1+1) 3 -> 2 4 -> 7 (=1+3+3) 5 -> 3 (=2+1) 6 -