Oh yes, that's even better! -- Bert
On Mon, Jun 24, 2013 at 10:33 AM, Rui Barradas <ruipbarra...@sapo.pt> wrote: > Hello, > > I had forgotten the much simpler solutions. The following should do it. > > split(dataset, dataset$ID) > > > Rui Barradas > > Em 24-06-2013 18:13, Bert Gunter escreveu: >> >> First of all, is your data structure a matrix or a data frame? They >> are different! >> >> Assuming the latter, a shorter version of Rui's answer that avoids >> unique() and automatically takes care of names is: >> >> result <- by(dataset, dataset$ID,I) >> >> See ?by, ?tapply, and ?split >> >> -- Bert >> >> On Mon, Jun 24, 2013 at 9:24 AM, Rui Barradas <ruipbarra...@sapo.pt> >> wrote: >>> >>> Hello, >>> >>> Try the following. >>> >>> >>> result <- lapply(unique(dataset$ID), function(uid) dataset[dataset$ID == >>> uid, ]) >>> names(result) <- unique(dataset$ID) >>> >>> >>> Hope this helps, >>> >>> Rui Barradas >>> >>> Em 24-06-2013 15:36, matteo escreveu: >>>> >>>> >>>> Hi guys, >>>> I'm a newby, so sorry for the easy question. >>>> >>>> I have a matrix (459x28) in which a large number of observations are >>>> repeated (same placed sampled in different times). >>>> One of the columns is refers to the ID of the place of sampling. >>>> What I would like is to extract subset matrix for every point of >>>> sampling. >>>> >>>> I can do it manually, e.g. x1<-data.frame(dataset[dataset$ID=="x1",]) >>>> but is it possible to write a script and let do it to R? >>>> So i got n submatrix of the n ID found in the original columns. >>>> >>>> Cheers >>>> >>>> Matteo >>>> >>>> ______________________________________________ >>>> 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. >> >> >> >> > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.
