Markus, You may also want to read the Help Desk article in the 8/1 R-News newsletter. It discusses the similarities and differences of *apply and loops and also shows the slowdowns from some common loops (that *apply tend to avoid).
Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] 801.408.8111 > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > project.org] On Behalf Of Mark Lyman > Sent: Wednesday, November 12, 2008 10:44 AM > To: [EMAIL PROTECTED] > Subject: Re: [R] apply() just loops ? > > Markus Loecher <mao.loecher <at> gmail.com> writes: > > > > > Dear R users, > > I have been diligently using the apply() family in order to avoid > explicit > > for loops and speed up computation. > > However, when I finally inspected the source code for apply, it > appears that > > the core computation is a simple loop as well. > > What am I missing ? Why the often found advice to use apply() instead > of > > loops and the actually observed empirical speedups on many tasks ? > > > > Thanks in advance for demystifying, > > > > Markus > > > > Professor Ripley gave the following response to a similar question, > that I > believe will answer your question. > > http://finzi.psych.upenn.edu/R/Rhelp02a/archive/76330.html > > Mark Lyman > > ______________________________________________ > 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.
