Noncentral chi-squared distribution with 0 degrees of freedom

[Stéphane Laurent <laurent_step@…>]

Hello,

Boost returns an error when we supply 0 for the degrees of freedom of chi-squared distribution:

#include <iostream>
#include <cmath>
#include "boost/math/distributions/non_central_chi_squared.hpp"

int main(){
    std::cout << boost::math::cdf(boost::math::non_central_chi_squared(0, 1), 1);
    return 0;
}

Error in function boost::math::non_central_chi_squared_distribution<double>::non_central_chi_squared_distribution(double,double): Degrees of freedom argument is 0, but must be > 0 ''

However this distribution makes sense. It has a density.

[John Maddock]

Moved to ​https://github.com/boostorg/math/issues/142