I do not know about details of numerical accuracy of R, it is probable related to numerical accuracy of C compiler that was used to compile it (gcc ?). However I would like to mention that I run into some problems with accuracy of sum and cumsum functions. See: > x = c(1, 1e20, 1e40, -1e40, -1e20, -1) > sum(x) [1] -1e+20 > cumsum(x) [1] 1e+00 1e+20 1e+40 0e+00 -1e+20 -1e+20 And wrote functions (with help of R-Help list) to address the problem. See sum.exact and cumsum.exact in caTools package: > sum.exact(x) [1] 0 > cumsum.exact(x) [1] 1e+00 1e+20 1e+40 1e+20 1e+00 0e+00 Jarek ====================================================\=======
Jarek Tuszynski, PhD. o / \ Science Applications International Corporation <\__,| (703) 676-4192 "> \ [EMAIL PROTECTED] ` \ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Talita Perciano Costa Leite Sent: Monday, June 27, 2005 10:57 AM To: [email protected] Subject: [R] Numerical accuracy Hi people, I need to prove the good quality of numerical accuracy of R. Anyone knows a paper or anything else comparing R to other statistical softwares in terms of numerical accuracy. I've made a long search about that but I found nothing. Please help me!! Thanx, Talita Leite ------------------------------------------------- Este e-mail foi enviado pelo Webmail da UFAL IMP: http://horde.org/imp/ ______________________________________________ [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 ______________________________________________ [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
