Your **is** the "coolest" and most efficient way to do this. It's vectorized -- apply() stuff is not.
Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Thu, Jun 18, 2015 at 12:40 PM, Frank S. <f_j_...@hotmail.com> wrote: > Hi everyone, > > I have an "x" vector and I would want to change the sign every 20 > elements. For this puspose, > I wrote the following code: > > set.seed(1) > x <- rnorm(100) > x > x[seq(20,100, by=20)] <- -x[seq(20,100, by=20)] > x > > However, I'm afraid it is a rudimentary form to get the desired result. > II wonder wether there is a cool way to do so, that is, for example with > apply or sign function. > > Thans in advanced for your help! > > Frank S. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
