On Tue, Apr 20, 2010 at 7:59 PM, Michael Hosack <mhosa...@hotmail.com> wrote: > > R experts, > > How could I extract the week number from a date vector (in Date class) > such that week numbering (week 1...2...) begins (May 01) and ends > (October 31) on the same specific dates each year? Week numbering > must conform to the following day numbering format > (Sat=1,Sun=2,Mon=3.....Fri=7). > This means that new weeks must begin on Saturdays, and end on Fridays > (except for the first date of May 01, which always begins week 1; week 2 > begins on the proceeding Saturday). This needs to be applicable across years > to work effectively. I have tried using both vectorized and loop approaches > with > no success. > > I am including a bit of old Systat code that does the trick simply and > concisely. > If anyone knows an analogous method in R please let me know. My R dataframe > contains > all the variables and data in the Systat temp file. > > Use sched3.t > Save sched4.t > Hold > By mm dd > If bof then let week=1 > Else if bog and DOW$="SAT" then let week = week + 1 > Run > > > Thank you, > > Mike > >
>From your code, it seems as if you're assuming that SCHEDULE3 contains all consecutive saturdays, without skipping any. Is that correct? /Gustaf ______________________________________________ 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.
