?sweep -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111
> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Maurits Aben > Sent: Thursday, August 05, 2010 2:00 PM > To: r-help@r-project.org > Subject: [R] Multiply each depth level of an array with another vector > element > > Suppose > > x <- array(c(1,1,1,1,2,2,2,2), dim = c(2,2,2)) > > y <- c(5, 10) > > > > Now I would like to multiply x[, , 1] with y[1] and x[, , 2] with y[2]. > > > > Possible solution is a for-loop: > > for (i in 1:2) { > > x[, , i] * y[i] > > } > > > > Another possible solution is this construction: > > as.vector(t(replicate(nrow(x) * ncol(x), y))) * x > > > > I find that these two solutions have a relatively large computation > time (on > larger arrays) and I suspect there should be solution with less > computation > time. Is there a faster method to perform this calculation (thus to > multiply > the depth of an array with respective vector elements)? > > > > Best regards, > > Maurits Aben > > [[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.
