Hello Jean

The problem seems that inside the functions stack/augment works in symbolical mode, and the input in symbolical mode is the one below, that is not managed by stack/augment (not sure if correct for symbolical calculations, bug or missing feature).
![2016-03-18 12_06_27-SMath Studio Desktop - [Fourier al_fftc1d_[ALGLIB][DEBUG].sm_].png](/en-US/file/ZMPTB7/2016-03-18-12_06_27-SMath-Studio-Desktop---_Fourier-al_fftc1d__ALGLIB__DEBUG__sm___png)
You have to place an eval() inside fft2D to force a numerical result.
Fourier al_fftc1d_[ALGLIB][DEBUG].sm (101 KiB) downloaded 64 time(s).Fourier al_[FFTPACK].sm (52 KiB) downloaded 65 time(s).
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