I don't know the answer, but would suppose not. You could test this for yourself using: system.time() example: system.time(rnorm(100000,0,1))
Chega wrote > > This solved my problem - Thanks a lot for your help! Please allow me one > more question: Works zoo's rollapply on a plain matrix faster than on a > zoo object? I am asking since I wanted to apply the provided averaging > code to a larger matrix (2500 rows x 200 cols), which is quite time > consuming... > > Thanks again! > > Chega > > ________________________________ > From: B77S [via R] <ml-node+s789695n4143909h3@.nabble> > To: Chega <chegaga@> > Sent: Friday, December 2, 2011 6:16 AM > Subject: Re: Moving column averaging > > > Sorry for that, and thanks Gabor, > I could have sworn that it wouldn't. > > > > Gabor Grothendieck wrote >>On Thu, Dec 1, 2011 at 7:13 PM, B77S <[hidden email]> wrote: >>> # need zoo to use rollapply() >>> >>> # your data (I called df) >>> df <- structure(list(a = 1:2, b = 2:3, c = c(5L, 9L), d = c(9L, 6L), >>> e = c(1L, 5L), f = c(4, 7)), .Names = c("a", "b", "c", "d", >>> "e", "f"), class = "data.frame", row.names = c(NA, -2L)) >>> >>> # transpose and make a zoo object >>> df2 <- zoo(t(df)) >>> >>> #rollapply to get means and transpose back >>> means <- t(rollapply(df2, width=2, by=2, FUN=mean)) >>> >>> # adding the combined column names you requested >>> colnames(means) <- apply(matrix(names(df), nrow=2), 2, paste, >>> collapse=", ") >>> >> >>Note that zoo's rollapply also works on plain matrices and vectors. >> >>-- >>Statistics & Software Consulting >>GKX Group, GKX Associates Inc. >>tel: 1-877-GKX-GROUP >>email: ggrothendieck at gmail.com >> >>______________________________________________ >>[hidden email] 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. > > ________________________________ > > If you reply to this email, your message will be added to the discussion > below: > http://r.789695.n4.nabble.com/Moving-column-averaging-tp4130179p4143909.html > To unsubscribe from Moving column averaging, click here. > NAML > -- View this message in context: http://r.789695.n4.nabble.com/Moving-column-averaging-tp4130179p4154770.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.