[Boost-users] [Beginner] Setting up a function which generates normally distributed numbers

Hello I'm sorry if this is answered in the documentation, but I didn't find it. I want a function which returns a normally distributed number. #include #include using namespace boost; double SampleNormal (double mean, double sigma) { mt19937 rng; // select random number generator rng.seed((unsigned int) time(0)); // seconds since 1970 // select desired probability distribution normal_distribution<double> norm_dist(mean, sigma); // bind random number generator to distribution, forming a function variate_generator normal_sampler(rng, norm_dist); // sample from the distribution return normal_sampler(); } This (from http://surl.se/tvk) works very well, except if it's invoked (with same parameters) more often than once a second. If so, the generator gets equal seeds and returns equal values. How can I construct my program so the seeding happens only once? My experience with templates is limited, but I do have a grasp of the idea. Thanks for any hints. Snorre Jakobsen, Norway