Which formula does randNorm use?

[parisse]

The CAS code for randNorm is

Code:


    double u=giac_rand(contextptr)/(rand_max2+1.0);
    double d=giac_rand(contextptr)/(rand_max2+1.0);
    return std::sqrt(-2*std::log(u))*std::cos(2*M_PI*d);

Frankly speaking I used the formula without taking care of why it works, it's not really CAS...