Dear colleagues,
Is there a way to order list items by date? I have a series of surveys in a list
where the name of each list item is the date the survey was taken but the list
items are out of order. Each data frame has a variable in it with the survey
date as well, if that helps.
Yours, Simon Kiss
#Sample Data
mylist<-list('1991-01-01'=data.frame(a=rep(5,5),
survey.date=rep(as.Date('1991-01-01', format='%Y-%m-%d'))),
'1979-01-01'=data.frame(aa=rep(5,5),
survey.date=rep(as.Date('1979-01-01', format='%Y-%m-%d'), 5)),
'2001-01-01'=data.frame(c=rep(6,5),
survey.date=rep(as.Date('2001-01-01', format='%Y-%m-%d'), 5)))
mylist
o <- order(as.Date(names(mylist))) myListInDateOrder <- mylist[o] Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf > Of Simon Kiss > Sent: Tuesday, November 20, 2012 8:41 AM > To: r-help at r-project.org > Subject: [R] Ordering List Items Chronologically > > Dear colleagues, > Is there a way to order list items by date? I have a series of surveys in a list where the > name of each list item is the date the survey was taken but the list items are out of order. > Each data frame has a variable in it with the survey date as well, if that helps. > Yours, Simon Kiss > #Sample Data > mylist<-list('1991-01-01'=data.frame(a=rep(5,5), survey.date=rep(as.Date('1991-01-01', > format='%Y-%m-%d'))), '1979-01-01'=data.frame(aa=rep(5,5), > survey.date=rep(as.Date('1979-01-01', format='%Y-%m-%d'), 5)), '2001-01- > 01'=data.frame(c=rep(6,5), survey.date=rep(as.Date('2001-01-01', format='%Y-%m-%d'), > 5))) > mylist > > ______________________________________________ > 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.
As long as all your names of list elements are in the same format, this should do it: mylist[order(names(mylist))] Thanks for the reproducible example, Sarah On Tue, Nov 20, 2012 at 11:40 AM, Simon Kiss <sjkiss at gmail.com> wrote:> Dear colleagues, > Is there a way to order list items by date? I have a series of surveys in a list where the name of each list item is the date the survey was taken but the list items are out of order. Each data frame has a variable in it with the survey date as well, if that helps. > Yours, Simon Kiss > #Sample Data > mylist<-list('1991-01-01'=data.frame(a=rep(5,5), survey.date=rep(as.Date('1991-01-01', format='%Y-%m-%d'))), '1979-01-01'=data.frame(aa=rep(5,5), survey.date=rep(as.Date('1979-01-01', format='%Y-%m-%d'), 5)), '2001-01-01'=data.frame(c=rep(6,5), survey.date=rep(as.Date('2001-01-01', format='%Y-%m-%d'), 5))) > mylist >-- Sarah Goslee http://www.functionaldiversity.org