/// <summary> /// Lanczos window. /// Periodic version, useful e.g. for FFT purposes. /// </summary> public static double[] LanczosPeriodic(int width) { double phaseStep = 2.0 / width; var w = new double[width]; for (int i = 0; i < w.Length; i++) { w[i] = Trig.Sinc((i * phaseStep) - 1.0); } return(w); }