Spectrum analysis windowing types.
Use this to reduce leakage of signals across frequency bands.
| Rectangular | W[n] = 1.0. |
| Triangle | W[n] = TRI(2n/N). |
| Hamming | W[n] = 0.54 - (0.46 * COS(n/N) ). |
| Hanning | W[n] = 0.5 * (1.0 - COS(n/N) ). |
| Blackman | W[n] = 0.42 - (0.5 * COS(n/N) ) + (0.08 * COS(2.0 * n/N) ). |
| BlackmanHarris | W[n] = 0.35875 - (0.48829 * COS(1.0 * n/N)) + (0.14128 * COS(2.0 * n/N)) - (0.01168 * COS(3.0 * n/N)). |