Patrizio Frederic wrote:
this works which.is.not.unique <- apply(x,2,function(x)ifelse(length(unique(x))==1,F,T)) x[,which.is.not.unique]
or you simplify that idea and say x[, apply(x, 2, function(x) length(unique(x)) > 1)] Uwe Ligges
patrizio 2009/3/26 Duijvesteijn, Naomi <naomi.duijveste...@ipg.nl>:Hi Readers, I have a question. I have a large dataset and want to throw away columns that have the same value in the column itself and I want to know which column this was. For example > x<-data.frame(id=c(1,2,3), snp1=c("A","G", "G"),snp2=c("G","G","G"),snp3=c("G","G","A")) > x id snp1 snp2 snp3 1 1 A G G 2 2 G G G 3 3 G G A Now I want to know that snp2 in monomorphic (the same value for the column) and after I know which column it is I want to take these columns out. Thanks, Naomi Disclaimer: De informatie opgenomen in dit bericht (en bijlagen) kan vertrouwelijk zijn en is uitsluitend bestemd voor de geadresseerde(n). Indien u dit bericht ten onrechte ontvangt, wordt u geacht de inhoud niet te gebruiken, de afzender direct te informeren en het bericht te vernietigen. Aan dit bericht kunnen geen rechten of plichten worden ontleend. ---------------------------------------------------------------------------- ---------------------------- Disclaimer: The information contained in this message may be confidential and is intended to be exclusively for the addressee. Should you receive this message unintentionally, you are expected not to use the contents herein, to notify the sender immediately and to destroy the message. No rights can be derived from this message. ______________________________________________ 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.
______________________________________________ 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.
