On Wed, Aug 25, 2010 at 7:56 AM, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > On Wed, Aug 25, 2010 at 7:43 AM, skan <juanp...@gmail.com> wrote: >> I have a zoo series. It lasts 10 years and its frequency is 15min. >> >> I'd like to get a new zoo series (or vector) with the same number of >> elements, whith each element equal to the first element of the day. That's, >> The first element everyday is repeated throughout the wole day. >> >> This is not same as aggregate(originalseries,as.Date,head,1) because this >> gives a vector with just one element for each day. > > Try ave: > >> library(zoo) >> library(chron) >> zz <- z <- zoo(1:100, chron(0:9/5))
That should have been 10, not 100; however, it ignored 11:100 so the answer is the same. >> zz[] <- ave(coredata(z), as.Date(time(z)), FUN = function(x) head(x, 1)) >> cbind(z, zz) > z zz > (01/01/70 00:00:00) 1 1 > (01/01/70 04:48:00) 2 1 > (01/01/70 09:36:00) 3 1 > (01/01/70 14:24:00) 4 1 > (01/01/70 19:12:00) 5 1 > (01/02/70 00:00:00) 6 6 > (01/02/70 04:48:00) 7 6 > (01/02/70 09:36:00) 8 6 > (01/02/70 14:24:00) 9 6 > (01/02/70 19:12:00) 10 6 > ______________________________________________ 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.
