private static float[] MakeChebychevLowPass(int filterOrder, double normalizedCutoff, double attenuation)
{
float[] array = FilterBuilder.MakeChebychevWindow(filterOrder, attenuation);
float[] array2 = FilterBuilder.MakeSinc(2.0, normalizedCutoff, array.Length);
FilterBuilder.ApplyWindow(array2, array);
FilterBuilder.Normalize(array2);
return(array2);
}