pei_tseng_notch [b, a] = pei_tseng_notch (frequencies, bandwidths) b = pei_tseng_notch (frequencies, bandwidths) frequencies: filter frequencies bandwidths: bandwidths to be used with filter This is an Octave function. It return coefficients for an IIR notch-filter with one or more filter frequencies and according bandwidths. The filter is based on a all pass filter that performs phasereversal at filter frequencies. This leads to removal of those frequencies of the original and phase-distorted signal.