> On Fri, 2003-03-21 at 09:06, John Hallam wrote: >> On Thu, 20 Mar 2003, Huard, Elise - D C&W Consultant wrote: >> >> > Or to phrase it differently : i need a random number generator that >> won't give the same sequence of numbers every time that the seed is >> reinitialised in the same second (by 2 different users) >> > srand(time(NULL)) >> > and then rand() >> > doesn't work. >> > Or a different kind of seed ? Suggestions are welcome (should be >> readily available in your standard Unix system) >> >> One thing you can do is to execute `ps' and hash the output, e.g. >> with MD5, and use some of those bits as your seed. There is enough >> going on in a PS output to make duplicate seeds rather unlikely, >> unless (perhaps) you have a multiple CPU machine which can execute >> multiple ps invocations simultaneously... >> >> As someone else said, be careful with rand() if you want good >> random sequences -- some rand()s are seriously broken. A good cheap >> random number generator is the Mersenne Twister, which you can find at >> http://www.math.keio.ac.jp/~matumoto/emt.html >> >> John. > > A white noise source connected to the sound card input would be a good > truly random number generator. > > _______________________________________________ > Scottish mailing list > [EMAIL PROTECTED] > http://mailman.lug.org.uk/mailman/listinfo/scottish
Now all we need to be able to do is create a true white noise source. Probably the best way to achieve this is to get a computer with a good software random number generator to produce random numbers and output them from a soundcard :). Thanks, Allan _______________________________________________ Scottish mailing list [EMAIL PROTECTED] http://mailman.lug.org.uk/mailman/listinfo/scottish