Another variation on the same theme : lst=list(m=c('a','b','c'),n=c('c','a'),l=c('a','bc')) set <- c('a','c')
f <-function(lst,set) sapply(lst,function(x) sum(set %in% x)==length(set) ) i <- f(lst,set) names(i[i]) Doesn't serve anybody but keeps my mind fresh. For long lists, you might benefit from first calculating the length of set, to avoid having to do that n times for a list of length n. Cheers Joris On Wed, Jun 23, 2010 at 11:01 PM, Peter Alspach <peter.alsp...@plantandfood.co.nz> wrote: > Tena koe Yu > > One possibility: > > lst[sapply(lst, function(x) length(x[x%in% c('a','c')])==2)] > > HTH ... > > Peter Alspach > >> -----Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- >> project.org] On Behalf Of Yuan Jian >> Sent: Thursday, 24 June 2010 1:35 a.m. >> To: r-help@r-project.org >> Subject: [R] list operation >> >> Hi, >> >> it seems a simple problem, but I can not find a clear way. >> I have a list: >> lst=list(m=c('a','b','c'),n=c('c','a'),l=c('a','bc')) >> > lst >> $m >> [1] "a" "b" "c" >> $n >> [1] "c" "a" >> $l >> [1] "a" "bc" >> >> how can I get list elements that include a given subset? for example, >> for given subset {'a','c'}, the answer should be 'm' and 'n'. >> >> thanks >> Yu >> >> >> >> [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Joris Meys Statistical consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control tel : +32 9 264 59 87 joris.m...@ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php ______________________________________________ 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.