Low-pass filter

The low-pass filter used in the algorithm is an adaptive butterworth filter. In the expert panel you can control the following parameters of the filter.

Roughness

The rougness determines how smooth the filtered spectra is. A high value of the roughness means that the filtered spectrum is smoother. This parameter is optimized in the parameter optimization.

Frequency cutoff:

The frequency cutoff parameter determines the initial value of the frequency cutoff in the adaptive butterworth filter. It is given in terms of the Nyquist-frequency. The value of this parameter has to be between 0 and 1 and it is optimized during the parameter optimization.
The algorithm can automatically find optimal values for both the frequency cutoff and the roughness parameter.