Hello, I ran my simulations on the Unix verson of R1.9.1 and the Windows version of R2.0.1 on XP. I kept getting different values for the mean of the same column of the same matrix, and am perplexed. I would appreciate if anyone could help explain the difference?
Here is a sample code: set.seed(7293) z1v <- rnorm(1000, mean=68, sd=13) z1v <- (z1v-mean(z1v))/sd(z1v) Using R1.9.1 on Unix, I get: mean(z1v) [1] -4.88775e-15 Using R2.0.1 on Windows XP, I get: mean(z1v) [1] -3.7497e-16 The same problem occurs when I dump the data from one version and then source it using the other version. Thanks for the help. Regards, Chang-Heok ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html