Or simply lapply(u, "[", 1) $a [1] 1
$b [1] "a" Cheers Petr > -----Original Message----- > From: R-help <r-help-boun...@r-project.org> On Behalf Of Eric Berger > Sent: Thursday, January 16, 2020 1:36 PM > To: R mailing list <r-help@r-project.org> > Subject: [R] Fwd: Extracting a particular column from list > > [Putting back onto r-help] > > You could try sapply() and lapply(). > > > e <- sapply( 1:length(u), function(i) u[[i]][1] ) e > # [1] "1" "a" (note that the integer 1 became a character string "1") > > > f <- lapply( 1:length(u), function(i) u[[i]][1] ) f > [[1]] > [1] 1 > > [[2]] > [1] "a" > > In this case sapply will try to create a vector, and all its elements will need to > be of the same type, so you end up with a character vector. > The second method returns a list, which may or may not be of use to you, > but each element of the list retains its type. > > > > ---------- Forwarded message --------- > From: Faheem Jan <faheemja...@yahoo.com> > Date: Thu, Jan 16, 2020 at 1:31 PM > Subject: Re: [R] Extracting a particular column from list > To: ericjber...@gmail.com <ericjber...@gmail.com> > > > In my problem i want to extract the first value of a and b and so on... So > using such data for further analysis > > Sent from Yahoo Mail on Android > <https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGro > wth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub > 2=Global_YGrowth&af_sub3=EmailSignature> > > On Thu, 16 Jan 2020 at 4:24 PM, Eric Berger <ericjber...@gmail.com> wrote: > > u <- list(a=1:5, b=letters[1:3]) > > u > # $a > # [1] 1 2 3 4 5 > # > # $b > # [1] "a" "b" "c" > > u[["a"]] > [1] 1 2 3 4 5 > > > > > > On Thu, Jan 16, 2020 at 1:04 PM Faheem Jan via R-help <r-help@r- > project.org> > wrote: > > Hi. How to extract a column from the list.. I will be thanks full.. > > Sent from Yahoo Mail on Android > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
