Note that Henrique's code does not give the same result as the expression you posted although its possible that his is what you really intended.
On Sun, Sep 27, 2009 at 10:27 AM, tzygmund mcfarlane <tzygm...@googlemail.com> wrote: > 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.
