Thanks Gabor - I'll check it out. Actually I just realised I can also do what I am looking for in a ridiculously simple manner (as the data I have is intra-day):
aggregate(l.zoo, hours(index(l.zoo)), mean) Cheers -- Rory On Jun 16, 2009 2:46pm, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > See R News 4/1. > On Tue, Jun 16, 2009 at 9:04 AM, rory.wins...@gmail.com> wrote: > > Hi all > > > > I have an irregular zoo series, where the time index looks like the > > following: > > > >> head(time(l.zoo)) > > > > [1] "2009-06-15 01:44:20.802 GMT" "2009-06-15 01:44:20.812 > GMT" "2009-06-15 > > 01:44:20.837 GMT" "2009-06-15 01:44:20.848 GMT" "2009-06-15 06:00:01.320 > > GMT" > > [6] "2009-06-15 06:00:01.330 GMT" > > > >> as.numeric(head(time(l.zoo))) > > > > [1] 1245030261 1245030261 1245030261 1245030261 1245045601 1245045601 > > > >> epoch + as.numeric(head(time(l.zoo))) > > > > [1] "2009-06-15 01:44:20.802 GMT" "2009-06-15 01:44:20.812 > GMT" "2009-06-15 > > 01:44:20.837 GMT" "2009-06-15 01:44:20.848 GMT" "2009-06-15 06:00:01.320 > > GMT" > > [6] "2009-06-15 06:00:01.330 GMT" > > > > > > What I would like to do is to run aggregate() over this zoo series, and > > compute a statistic over say a 5-minute or 1-hour interval. However, I > cant > > seem to get chron() to figure out the right dates: > > > >> chron(as.numeric(head(time(l.zoo)))) > > > > [1] (01/28/47 19:14:53) (01/28/47 19:29:17) (01/28/47 20:05:17) > (01/28/47 > > 20:21:07) (01/28/89 07:40:48) (01/28/89 07:55:12) > > > >> epoch > > [1] "1970-01-01 GMT" > > > > > >> chron(as.numeric(head(time(l.zoo))), origin.=epoch) > > [1] (12/20/64 19:14:53) (12/20/64 19:29:17) (12/20/64 20:05:17) > (12/20/64 > > 20:21:07) (12/22/06 07:40:48) (12/22/06 07:55:12) > > > > Does anyone know what I am doing wrong here? > > > > Cheers > > -- Rory > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > [[alternative HTML version deleted]] ______________________________________________ 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.
