If you are using rbind() at each iteration, that can slow things down greatly. Look up a document called the R Inferno which discusses this in great detail in circle 2.
Michael Weylandt On Mon, Oct 3, 2011 at 2:26 PM, Cable, Sam B Civ USAF AFMC AFRL/RVBXI <sam.ca...@kirtland.af.mil> wrote: > More on my previous question ... > > I have put in timing statements to try to get a better idea of where the > problem is, like so: > > conn<-file('filename','r') > > for (chunk in 1:100000) { > print(paste('begin read at',date())) > Lines<-readLines(conn,n=25) > print(paste('begin processing at',date())) > # process "Lines" > print(paste('end loop at',date())) > } > > Every time I go through the loop, all the date() functions return > *exactly* the same time! It *looks like* it runs through each iteration > very quickly and then takes longer and longer to simply start the next > iteration. I don't believe this. I think R must be doing some kind of > latency trick or something. But, anyway, the point is that I was > assuming the problem was in the I/O, and now I don't know if it's I/O or > processing. Either way, I don't understand it and would really > appreciate some wisdom from you guys. > > 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.