Hi Hossein, On Wed, Jul 28, 2010 at 10:33 AM, Hossein Haeri <powerprogman@yahoo.com> wrote:

Dear all,

When I run the following simple code, the output is "-1.#IND" in MSVC 2008 and "nan" in GCC 4.4.0. I guess that means something is not initialised yet... So, what's missing here?

boost::normal_distribution<double> gen; boost::mt19937 engine; double r = gen(engine); cout << r;

Looks like you're forgetting to pass both arguments to the variate_generator -- the item you marked as gen is really a distribution. Try the following: #include "boost/random/mersenne_twister.hpp" #include "boost/random/normal_distribution.hpp" #include "boost/random/variate_generator.hpp" #include <iostream> int main() { boost::normal_distribution<double> dist; boost::mt19937 engine; boost::variate_generator<boost::mt19937&, boost::normal_distribution<double> > gen(engine, dist); double r = gen(); std::cout << r; return 0; } HTH, Nate