Forgot to cc the list... ---------- Forwarded message ---------- From: Peter Langfelder <[email protected]> Date: Sat, Jul 9, 2016 at 1:32 PM Subject: Re: [R] How to make the "apply" faster To: Debasish Pai Mazumder <[email protected]>
You could try the following (I haven't tested it so check that the results make sense): indicator = x>=70; new = apply(indicator, c(1,2,4), sum); If you could find a way to make the dimension over which you sum the last (or first), you could use rowSums (or colSums) on indicator which would be orders of magnitude faster. Peter On Sat, Jul 9, 2016 at 1:19 PM, Debasish Pai Mazumder <[email protected]> wrote: > I have 4-dimension array x(lat,lon,time,var) > > I am using "apply" to calculate over time > new = apply(x,c(1,2,4),FUN=function(y) {length(which(y>=70))}) > > This is very slow. Is there anyway make it faster? > > -Debasish > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. ______________________________________________ [email protected] 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.
