Has anyone implemented or experimented with the Fractional Fourier Transform (FrFT) in Pure Data and might point me to relevant resources? So far, I badly failed at implementing an external that would allow continuous rotation between time and frequency domains (see https://en.wikipedia.org/wiki/Fractional_Fourier_transform).

I've heard about quite interesting musical applications of this in a talk and demos by Günther Rabl (who implemented this years ago in his own tools AMP/VASP) and would love to experiment with it in Pd.