HI, I have the list:> suu[[1]] NULL [[2]] NULL [[3]] item_id prod 1 2 [[4]] item_id prod 1 2 2 4 how to delete all "NULL" elements from suu to get only>suu[[3]] item_id prod 1 2 [[4]] item_id prod 1 2 2 4 ?? Kind regards, Tammy [[alternative HTML version deleted]]
Hello, Try the following. suu <- list(NULL, NULL, 1:2, matrix(1:4, 2)) suu[!sapply(suu, is.null)] Hope this helps, Rui Barradas Em 25-01-2013 12:31, Tammy Ma escreveu:> > HI, > > I have the list: > > >> suu > [[1]] > NULL > > [[2]] > NULL > > [[3]] > item_id prod > 1 2 > > [[4]] > > item_id prod > 1 2 > 2 4 > > > > how to delete all "NULL" elements from suu to get only > >> suu > > [[3]] > item_id prod > 1 2 > > [[4]] > > item_id prod > 1 2 > 2 4 > > > ?? > > > Kind regards, > Tammy > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. >
Tammy Ma <metal_licaling <at> live.com> writes:> > suu > [[1]] > NULL > [[2]] > NULL > [[3]] > item_id prod > 1 2 > [[4]] > item_id prod > 1 2 > 2 4 > > how to delete all "NULL" elements from suu to get only > > >suu > [[3]] > item_id prod > 1 2 > [[4]] > item_id prod > 1 2 > 2 4How about suu[!sapply(suu,is.null)] ? (Haven't tested, but I would expect it to work ... Of course, the result won't have elements [[3]] and [[4]], it will have elements [[1]] and [[2]] ... Ben Bolker
Or, suu[unlist(lapply(suu,length)!=0)] #[[1]] #[1] 1 2 #[[2]] ?# ?? [,1] [,2] #[1,]??? 1??? 3 #[2,]??? 2??? 4 A.K. ----- Original Message ----- From: Rui Barradas <ruipbarradas at sapo.pt> To: Tammy Ma <metal_licaling at live.com> Cc: "r-help at r-project.org" <r-help at r-project.org> Sent: Friday, January 25, 2013 8:15 AM Subject: Re: [R] how to delete the null elements in list Hello, Try the following. suu <- list(NULL, NULL, 1:2, matrix(1:4, 2)) suu[!sapply(suu, is.null)] Hope this helps, Rui Barradas Em 25-01-2013 12:31, Tammy Ma escreveu:> > HI, > > I have the list: > > >> suu > [[1]] > NULL > > [[2]] > NULL > > [[3]] > item_id? prod >? 1? ? ? ? ? 2 > > [[4]] > > item_id prod > 1? ? ? ? ? 2 > 2? ? ? ? ? 4 > > > > how to delete all "NULL" elements from suu to get only > >> suu > > [[3]] > item_id? prod >? 1? ? ? ? ? 2 > > [[4]] > > item_id prod > 1? ? ? ? ? 2 > 2? ? ? ? ? 4 > > > ?? > > > Kind regards, > Tammy > >? ??? ??? ??? ? ??? ??? > ??? [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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 at 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.