Function rand_normal

yolo_detector/darknet_opt/src/utils.c:642–661

From http://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform

// From http://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform
float rand_normal()
{
    static int haveSpare = 0;
    static double rand1, rand2;

    if(haveSpare)
    {
        haveSpare = 0;
        return sqrt(rand1) * sin(rand2);
    }

    haveSpare = 1;

    rand1 = rand() / ((double) RAND_MAX);
    if(rand1 < 1e-100) rand1 = 1e-100;
    rand1 = -2 * log(rand1);
    rand2 = (rand() / ((double) RAND_MAX)) * TWO_PI;

    return sqrt(rand1) * cos(rand2);
}

/*
   float rand_normal()