See ?window.zoo Also suggest you use dput to display sample data in posts to r-help.
On Tue, Jun 16, 2009 at 1:19 PM, <rory.wins...@gmail.com> wrote: > Hi guys > > Does anyone know if it is possible to index a zoo series by a sequence? For > instance, with the following irregular zoo object, I can calculate the range > of its time-based index: > >> r <- range(index(l.zoo)) >> r > [1] "2009-06-15 01:44:20.802 GMT" "2009-06-15 16:54:24.124 GMT" > > If I just want to be able to extract the last 1 minutes worth of data, I > would like to be able to do something like the following: > >> r.1min <-range(r[2]-60, r[2]) >> r.1min > [1] "2009-06-15 01:44:20.802 GMT" "2009-06-15 16:54:24.124 GMT" > > last.minute <- l.zoo[ index(l.zoo) %in% r.1min] > > This doesnt work, as it is doing a straight subset check (which is > appropriate). So I am using the following method: > > last.minute <- l.zoo[ index(l.zoo) >= (r[2]-60)] > > is this the best way to do this (I suspect not)? > > -- Rory > > > > > > > > On Jun 16, 2009 2:52pm, rory.wins...@gmail.com wrote: >> 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. >> > >> > > >> > ______________________________________________ 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.
