Thanks Jonathan and Ista, that's really helpful. Got it running much better now.
Ben On 2 March 2011 17:33, Jonathan P Daily <jda...@usgs.gov> wrote: > Is this what you want? I don't know what your v looks like, but this won't > work if there are cases in which v won't sum to exactly x. > > x <- 20 > v <- sample(0:1, 100, T) > > w <- v[1:which(cumsum(v)==x)] > -------------------------------------- > Jonathan P. Daily > Technician - USGS Leetown Science Center > 11649 Leetown Road > Kearneysville WV, 25430 > (304) 724-4480 > "Is the room still a room when its empty? Does the room, > the thing itself have purpose? Or do we, what's the word... imbue it." > - Jubal Early, Firefly > > r-help-boun...@r-project.org wrote on 03/02/2011 10:42:12 AM: > > > [image removed] > > > > [R] Vector manipulations > > > > Benjamin Hartley > > > > to: > > > > r-help > > > > 03/02/2011 11:08 AM > > > > Sent by: > > > > r-help-boun...@r-project.org > > > > I have a question regarding the most efficient way to select a substring > of > > a vector: > > > > I have a vector of value v, and I want to select a subspace of this > vector > > called w such that: > > > > w=v[1:n] > > > > where > > > > sum(w) = x > > > > I am interested in what you thing would be the most efficient way to do > this > > - I would like to avoid slowing down my simulations as much as possible. > > > > Thank you very much for any help that anyone is able to give. > > > > [[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.
