/// <summary>
/// Estimates the unbiased population standard deviation from the provided samples.
/// On a dataset of size N will use an N-1 normalizer (Bessel's correction).
/// Returns NaN if data has less than two entries or if any entry is NaN.
/// </summary>
/// <param name="samples">A subset of samples, sampled from the full population.</param>
public static double StandardDeviation(this IEnumerable <double> samples)
{
var array = samples as double[];
return(array != null
? ArrayStatistics.StandardDeviation(array)
: StreamingStatistics.StandardDeviation(samples));
}