function BlackmanOptimal(const Src: TVec; Index: Integer; Len: Integer): TVec;
Optimal Blackman window.
| # | Name | Type | Description |
|---|---|---|---|
| 1 | Src | TVec | |
| 2 | Index | Integer | start index |
| 3 | Len | Integer | element count |
Returns: TVec
Remarks:
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:
w[n] = (alpha + 1)/2 - 0.5cos((2pi n)/(n-1)) - alpha/2cos((4pi n)/(n-1)) alpha = -((sin(pi/(n-1)))/( ) sin(2pi/(n-1)))^2