FFTW3¶

user manual

Official Tutorial

meeting with Ju-an Zhang (2024-01-04)

• column-major convention note
• normalization convention [ \mathrm{invFFT}(\mathrm{fwdFFT}(f(x))) = Nx * f(x) ]
• using FFTW_MEASURE or FFTW_ESTIMATE in fft plan (referred doc): in short, if need to use the same setting many times use FFTW_MEASURE (getting optimzed performance parameters by measuring the current system); otherwise, use FFTW_ESTIMATE to get a default set of parameters (sidestep the overhead of measurement).