static T Random <T>(IEnumerable <T> ts, MersenneTwister r, bool throws)
{
var xs = ts as ICollection <T>;
xs = xs ?? ts.ToList();
if (xs.Count == 0)
{
if (throws)
{
throw new ArgumentException("Collection must not be empty.", "ts");
}
else
{
return(default(T));
}
}
else
{
return(xs.ElementAt(r.Next(xs.Count)));
}
}
// Sampled a N-sample probability density function in the range [-1024..1024]
// 1 sample produces a rectangular probability
// 2 samples produces a triangular probability
// ...
// N samples approximates a true Gaussian
public static WDist FromPDF(MersenneTwister r, int samples)
{
return(new WDist(Exts.MakeArray(samples, _ => r.Next(-1024, 1024))
.Sum() / samples));
}