On Mon, Feb 18, 2002 at 07:27:03AM +0000, Richard Proctor wrote: > On Mon 18 Feb, James Taylor wrote: > > On Fri 15 Feb, James Taylor wrote: > > > > > > The rand() function as implemented in RISC OS Perl 1.13 for > > > the RiscPC is *not* uniform as it should be. > > > > Err... It's been awfully quiet since I posted that. > > Been busy
Been in Germany for the Fourth German Perl Workshop. > > Is there anybody there? > > Yes As for previous answer, plus there was no public e-mail access there. > > Does anybody care? > > Yes. The rand function in the current riscos perl is based on the C > function"rand", which is well known to be less the ideal. if/when we move > riscos perl to the more recent version which uses the C fucntion rand48 which > is more random. As Richard says, assuming that one has an implementation of rand48 for RISC OS. I've not looked into random number stuff ever, but my understanding of the C rand() function is what Richard says. My general understanding about random numbers on computers is that the question to ask is 'well, how "random" do you want it?' in that it's very hard for an essentially non-random machine to fake "random" numbers for you; that there are different tests for "randomness", different ways of generating pseudo random numbers that pass different combinations of the "randomness" tests, and that no method is perfect. Nicholas Clark -- EMCFT http://www.ccl4.org/~nick/CV.html
