And are you able to give an explanation? For example, did you compile each under the same compiler system?
I doubt if this is worth R-core's time to pursue, so over to interested users to find an explanation and fix. On Mon, 4 Aug 2003, James MacDonald wrote: > I get similar results as Philippe on WinXP (1.33 GHz laptop, 512 Mb > RAM). > > R 1.7.1 > 2.86 sec > 7.82 sec > > R 1.7.0 > 0.64 sec > 1.64 sec > > Jim > > > > > James W. MacDonald > Affymetrix and cDNA Microarray Core > University of Michigan Cancer Center > 1500 E. Medical Center Drive > 7410 CCGC > Ann Arbor MI 48109 > 734-647-5623 > > >>> Peter Dalgaard BSA <[EMAIL PROTECTED]> 08/04/03 11:30AM >>> > "Philippe Grosjean" <[EMAIL PROTECTED]> writes: > > > I do not understand what happens here (under Win XP): > > > > a <- abs(matrix(rnorm(800*800)/2, ncol=800, nrow=800)) > > system.time(b <- a^1000)[3] > > > > took about 1 sec on my computer with R 1.7.0 and it takes now 4.59 > sec with > > R 1.7.1 > > > > Similarly, > > > > phi <- 1.6180339887498949 > > a <- floor(runif(750000)*1000) > > system.time(b <- (phi^a - (-phi)^(-a))/sqrt(5))[3] > > > > took about 0.9 sec with R 1.7.0, and it takes 11.8 sec (!!!) in R > 1.7.1. > > > > Are there some changes made between 1.7.0 and 1.7.1 that could cause > such a > > large difference in time to do such simple computations??? > > Hmm, on linux, I get approx 0.31 for the first example with 1.7.0, > 1.7.1, r-patched, and r-devel. Similarly, I get 0.8 for the second ex. > in all four cases. > > -- 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://www.stat.math.ethz.ch/mailman/listinfo/r-help
