Thanks. I also did some parallel computing. Here are some time I spent by using 'snowfall' package on intel centrino 2 laptop (2 cores) on windows 7.
user system elapsed 0.24 0.05 2442.77 Libo On Wed, Feb 22, 2012 at 12:53 AM, Martin Maechler < maech...@stat.math.ethz.ch> wrote: > >>>>> "LS" == Libo Sun <libo...@rams.colostate.edu> > >>>>> on Tue, 21 Feb 2012 21:09:54 -0700 writes: > > > Thanks. Shall I sum the user time and system time, which > > roughly equals to the elapsed time? > > No. Rather just use the user time, > i.e. proc.time()[[1]] > system.time()[[1]] etc > > That's typically good enough [as long as you don't use > internally multithreaded BLAS, or parallelize / distribute your job, > or other things you won't be doing (yet)]. > > Martin Maechler, ETH Zurich > > > I also tried to improve the code by using 'cmpfun(myfunction)' in > > 'compiler' package, however, it doesn't help too much. > > > Libo > > > On Tue, Feb 21, 2012 at 8:11 PM, R. Michael Weylandt < > > michael.weyla...@gmail.com> wrote: > > > The time relationships aren't strictly linear between any of the three > > measures, but *very generally* I've interpreted them as something > > like: > > > > User: stuff you do (i.e., doing all the commands) > > System: stuff at the OS level (memory allocations and whatnot) > > Elapsed: Clock time > > > > None is a great measure in isolation, but the system time is not the > > worrisome one here: it looks like your script takes about a day and a > > half to run....that might be ok (and perhaps unavoidable) but it looks > > like there might be value in trying to squeeze some speed out of your > > script. A simple thing like byte-compiling that gives 2x speedup would > > be huge here. > > > > Michael > > > > On Tue, Feb 21, 2012 at 10:06 PM, Libo Sun <libo...@rams.colostate.edu> > > wrote: > > > Hi all, > > > > > > I got this time for my code, > > > > > >> proc.time()-pt > > > user system elapsed > > > 132541.743 0.004 132533.526 > > > > > > As you can see, there is huge difference btw elapsed time and system > > time. > > > Does that mean lots of I/O? Or some bad coding? > > > > > > Thanks, > > > Libo > [[alternative HTML version deleted]] ______________________________________________ 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.