On Wed, Oct 9, 2013 at 11:49 AM, Berend Hasselman <b...@xs4all.nl> wrote: > > On 09-10-2013, at 13:50, Ronald Peterson <r...@hub.yellowbank.com> wrote: > >> Hi, >> >> New to R here. Lots of fun. Still rather green though. >> >> I'd like to select unique items from a list that looks like this (for >> example): >> >>> xyz >> $x >> [1] 8 6 9 0 0 3 9 7 1 9 >> $y >> [1] 1 2 9 5 1 2 0 9 2 9 >> $z >> [1] 5 6 9 0 5 1 1 7 3 4 >> >> I'd like to select unique (x,y), while preserving association with z >> values. When there are duplicate (x,y) pairs, it doesn't really matter >> which (x,y,z) triplet gets preserved - selecting the first would be fine, >> but any other way to do it would be fine also. It /would/ be handy to also >> get a list of the rejected triplets, if that's possible. Ideas? > > You could try this > > A <- cbind(xyz[[1]],xyz[[2]]) > A > > indx <- which(duplicated(A)) > indx > > lapply(xyz,function(u) u[-indx]) > lapply(xyz,function(u) u[indx])
or even indx <- duplicated(A)) lapply(xyz,function(u) u[!indx]) lapply(xyz,function(u) u[indx]) Fear not logical indexing! ;-) -- Bert > > > Berend > > ______________________________________________ > 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 (650) 467-7374 ______________________________________________ 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.