On Tue, 14 Sep 2004, Adaikalavan Ramasamy wrote: > Many thanks to Prof. Ripley. The problem is that memory.profile does not > exist in *nix environment and there is probably a very good reason why.
memory.size? > > I was reading help(Memory) and in the Details section : > You can find out the current memory consumption (the heap and cons > cells used as numbers and megabytes) by typing 'gc()' at the R > prompt. > > AFAICS, Ncells is the fixed memory used by the underlying R and Vcells > is the variable part and depends on the calculations. > > Would I be able to say that the generating 10 million random numbers > requires approximately 73.4 Mb (= 26.3 + 80.5 - 26.3 - 7.1) of memory ? > I double checked this against memory.size() in Windows and they seem to > agree. Thank you. No, only that storing 10 million numbers requires 77.3 - 1.0Mb, and > object.size(x)/1024^2 [1] 76.29397 > > gc() > used (Mb) gc trigger (Mb) > Ncells 456262 12.2 984024 26.3 > Vcells 122697 1.0 929195 7.1 > > > > x <- rnorm(10000000) > > gc() > used (Mb) gc trigger (Mb) > Ncells 456274 12.2 984024 26.3 > Vcells 10123014 77.3 10538396 80.5 > > > > > On Mon, 2004-09-13 at 18:47, Prof Brian Ripley wrote: > > On Mon, 13 Sep 2004, Adaikalavan Ramasamy wrote: > > > > > I am comparing two different algorithms in terms of speed and memory > > > usage. I can calculate the processing time with proc.time() as follows > > > but am not sure how to calculate the memory usage. > > > > > > ptm <- proc.time() > > > x <- rnorm(1000000) > > > proc.time() - ptm > > > > Hmm ... see ?system.time! > > > > > I would like to be within R itself since I will test the algorithm > > > several hundred times and in batch mode. So manually looking up 'top' > > > may not be feasible. help.seach("memory") suggests memory.profile and gc > > > but I am not sure how to use these. > > > > I don't think you can. You can find out how much memory R is using NOW, > > but not the peak memory usage during a calculation. Nor is that > > particularly relevant, as it depends on what was gone on before, the word > > length of the platform and the garbage collection settings. > > > > On Windows, starting in a clean session, calling gc() and memory.size(), > > then calling your code and memory.size(max=TRUE) will give you a fair > > idea, but `top' indicates some Unix-alike. > > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html