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
