Thank you Gabor (& Henrique)! On Sun, Sep 27, 2009 at 3:26 PM, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > with(attenu, mag + as.numeric(station)) > > is nearly twice as fast: > >> system.time(for(i in 1:1000) with(attenu, mag + as.numeric(station))) > user system elapsed > 0.05 0.02 0.06 > >> system.time(for(i in 1:1000) rowSums(cbind(mag, station))) > user system elapsed > 0.09 0.00 0.10 > > See ?system.time, ?Rprof and http://code.google.com/p/rbenchmark/ > for timing commands. > > On Sat, Sep 26, 2009 at 11:16 AM, tzygmund mcfarlane > <tzygm...@googlemail.com> wrote: >> Hi, >> >> For very large matrices, is this the most efficient way to add two >> variables together? >> >> ############################# >> attach(attenu) >> new<-rowSums(cbind(mag, station)) >> ############################# >> >> Also, could I be directed to some resources for working with very >> large datasets? >> >> Thanks >> >> ______________________________________________ >> 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.
