, ( ):
static Random r = new Random();
static double Normal(double mu, double sig)
{
double u, v, x, y, q;
do
{
u = r.NextDouble();
v = 1.7156 * (r.NextDouble() - 0.5);
x = u - 0.449871;
y = Math.Abs(v) + 0.386595;
q = Math.Sqrt(x) + y * (0.19600 * y - 0.25472 * x);
} while (q > 0.27597 && (q > 0.27846 || Math.Sqrt(v) > -4.0 * Math.Log(u) * Math.Sqrt(u)));
return mu + sig * v / u;
}