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. -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
