I do not have the tenacity to decipher your logic, but I would suggest that you go through an R tutorial or two instead of limiting yourself to R-Help (not R forum?) archives. You probably are going about it wrongly in R (I suspect you need indexing). In fact, I would guess that you probably don't want to go about things this way at all in R, but of course that would require my knowing the underlying problem you are trying to solve, which I do not. My point is that you need to change your programming paradigm and learn R instead of trying to overlay SAS paradigms. And yup, it requires time and effort to do this.
Note that there are various "R for SAS programmers" tutorials out there, which might be helpful, either for your specific query or more generally. Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Apr 19, 2016 at 3:59 PM, pele.s--- via R-help <r-help@r-project.org> wrote: > Hello, > > Iam looking for an R solution that can efficiently produce the output shown > below. I can produce this easily in SAS with retain statement and a few lines > of if-then-else logic, etc.. but I am not find anything similar on the Rforum > archives. Below is the logic I am trying to apply to produce the output table > below. Thanks in any help! > > if the ID is the first ID encountered then group=1 and groupdate=date or else > if not first ID and date - previous date > 10 or date - previous group date > >10 then group=previous group # + 1 and groupdate = date or else if not first > ID and date - previous date <= 10 or date - previous group date<=10 then > group=previous group # and groupdate = previous date. > > Input: > > ID DATE ITEM > 1 1/1/2014 P1 > 1 1/15/2014 P2 > 1 1/20/2014 P3 > 1 1/22/2014 P4 > 1 3/10/2015 P5 > 2 1/13/2015 P1 > 2 1/20/2015 P2 > 2 1/28/2015 P3 > 2 2/28/2015 P4 > 2 3/20/2015 P5 > Desired Output > > ID DATE ITEM GROUP GROUPDATE > 1 1/1/2014 P1 1 1/1/2014 > 1 1/15/2014 P2 2 1/15/2014 > 1 1/20/2014 P3 2 1/15/2014 > 1 1/22/2014 P4 2 1/15/2014 > 1 3/10/2015 P5 3 3/10/2015 > 2 1/13/2015 P1 1 1/13/2015 > 2 1/20/2015 P2 1 1/13/2015 > 2 1/28/2015 P3 2 1/28/2015 > 2 2/28/2015 P4 3 2/28/2015 > 2 3/20/2015 P5 4 3/20/2015 > > Thanks for any help! > > ______________________________________________ > 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.
