Hi, On Fri, Nov 11, 2011 at 7:26 AM, Oliver <oli...@first.in-berlin.de> wrote: > Christofer Bogaso <bogaso.christofer <at> gmail.com> writes: > [...] >> Here my question is, is there any speed reduction if I put them within a >> function (I think there may be some speed reduction at least within >> for-loop, because that loop needs to call that function many times), >> relative to if I used that group of codes as-it-is in many places? > [...] > > > You did not asked for it, you may know it, or may not know it: > if you use apply functions and other vector oriented functions, > this can bring you a huge speedup, compared to a for-loop.
I don't think this is exactly true. I believe the majority *apply functions are really more-or-less just sugar that boil down to having a for loop buried within them. This is just to say that I'm not sure how much of a speedup anybody should expect switching from a `for` loop to `*apply` function (assuming you aren't growing an array w/in each iteration of a for loop, for example), but if you can replace the for/*apply loop with a few lines of vectorized functions, then yeah -- you can expect big gains. -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.
