Quote:Original post by nightechQuote:Original post by Sync Views
3.044e-005 <--ok...so why are there results over 1?
3.044e-005 is scientific notation for 0.00003044 ;) so it's not generating over 1 at all, just closer to 0.
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Now what i'm wondering is how come it's faster than the standard rand() that I assumed was optimised?
Quote:Original post by DevFred
I would actually love to writebut of course a number one greater than the maximum is very unlikely to existdiv = (std::numberic_limits<unsigned>::max() + 1) / bound; return operator()() / div;
Quote:Original post by Bregma
Writing a simple PRNG is not as easy as it appears.
Quote:Original post by Bregma
the last resort is to write your own Pseudo Random Number Generator class
class mt : public Random{ boost::mt19937 mt((unsigned)time(NULL)); public: virtual double Uniform() { static boost::variate_generator <boost::mt19937& ,boost::uniform_real<>> rng(mt,boost::uniform_real<>(0,1));//Is this 0 <= x < 1? The docs don't seem to say... return rng(); } virtual double Uniform(double Min, double Max( { //Isn't there a way to avoide creating all this for EVERY number? //but then wouldn't multipliying the above be pretty bad having already mapped it to 0...1? boost::variate_generator <boost::mt19937& ,boost::uniform_real<>> rng(mt,boost::uniform_real<>(Min, Max); return rng(); }};Quote:Original post by Sync Views
Isn't there a way to avoide creating all this for EVERY number?
#include <iostream>#include <boost/random.hpp>int main(){ boost::mt19937 generator(42u); boost::uniform_real<> uni_dist(0, 1); boost::variate_generator<boost::mt19937&, boost::uniform_real<> > uni(generator, uni_dist); for (int i = 0; i < 100; ++i) std::cout << uni() << std::endl;}
