Thank you very much, Thierry! Really amazing, the magic melt from reshape. And, in fact, a bit dangerous - it just do what I need without any efforts on my part! Dimitri
On Thu, Apr 23, 2009 at 10:40 AM, ONKELINX, Thierry <thierry.onkel...@inbo.be> wrote: > Dear Dimitri, > > Have a look at melt() from the reshape package. > > X<-matrix(c(10,20,30,40,50,60),2,3) > dimnames(X)<-list(c("1","2"),c("1","2","3")) > library(reshape) > melt(X) > > HTH, > > Thierry > > > ------------------------------------------------------------------------ > ---- > ir. Thierry Onkelinx > Instituut voor natuur- en bosonderzoek / Research Institute for Nature > and Forest > Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, > methodology and quality assurance > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > tel. + 32 54/436 185 > thierry.onkel...@inbo.be > www.inbo.be > > To call in the statistician after the experiment is done may be no more > than asking him to perform a post-mortem examination: he may be able to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The plural of anecdote is not data. > ~ Roger Brinner > > The combination of some data and an aching desire for an answer does not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > -----Oorspronkelijk bericht----- > Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > Namens Dimitri Liakhovitski > Verzonden: donderdag 23 april 2009 16:31 > Aan: R-Help List > Onderwerp: [R] transposing a matrix - row by row? > > Hello, > I have a matrix that is a product of tapply on a larger data set. > Let's assume it looks like this: > > X<-matrix(c(10,20,30,40,50,60),2,3) > dimnames(X)<-list(c("1","2"),c("1","2","3")) > (X) > > 1 2 3 > 1 10 30 50 > 2 20 40 60 > > Is there an efficient way of transforming this matrix into the following > matrix: > > rows columns entries > 1 1 10 > 1 2 30 > 1 3 50 > 2 1 20 > 2 2 40 > 2 3 60 > > > Thank you very much! > -- > Dimitri Liakhovitski > MarketTools, Inc. > dimitri.liakhovit...@markettools.com > > ______________________________________________ > 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. > > Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer > en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd > is > door een geldig ondertekend document. The views expressed in this message > and any annex are purely those of the writer and may not be regarded as > stating > an official position of INBO, as long as the message is not confirmed by a > duly > signed document. > -- Dimitri Liakhovitski MarketTools, Inc. dimitri.liakhovit...@markettools.com ______________________________________________ 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.