Biquadratic Filter Design Function

Calculate numerator and denominator coefficients for biquadratic filters

This MATLAB function calculates the numerator and denominator coefficients for three types of digital biquadratic filters used in audio signal processing: bass shelf filter, treble shelf filter, and peak filter. The algorithm, which is described in detail in an accompanying document, makes use of the MATLAB bilinear function and straightforward formulas for the corresponding analog filters.