The Fourier transform library FFTW does this too. Its "wisdom" system will plan/measure the best way to do transforms of a particular size/type and cache it fo

The Fourier transform library FFTW does this too. Its "wisdom" system will plan/measure the best way to do transforms of a particular size/type and cache it for future use. More here: https://www.fftw.org/fftw3_doc/Words-of-Wisdom_002dSaving-Plans.html https://www.fftw.org/fftw3_doc/Words-of-Wisdom_002dSaving-Pl...