BlackmanOptimal Routine

Summary

Optimal Blackman window.

Declaration

Function BlackmanOptimal(Src: TVec; Index: integer = 0; Len: integer = -1): TVec;

Description

Applies optimal Blackman window to Src. Window functions are applied to the signal prior to conversion to frequency domain with the FFT algorithm, to reduce the spectral leakage. Their side-effect is a lower frequency resolution. The following function defines the Blackman window:


            alpha + 1            2*Pi*n       alpha        4*Pi*n
    w[n] = ---------- - 0.5*cos --------  -  ------ * cos(-------)
               2                 n - 1          2          n - 1

                sin(Pi/(n-1))
    alpha = - (---------------)^2
               sin(2*Pi/(n-1))