Report DFT progress

[meiyasan]

Hello,

I would like to make a progress bar when computing large Fourier transform. This would be a great feature..
Knowing the total number of Fourier coefficients to compute and the typical FFT flow graphs.. Is there any possibility to use a signal handler to report the computational progress of the calculation ?

Cheers,
Marco

[dancazarin]

Hello Marco,
I think it's not possible without modifying KFR sources.
Progress callback is not implemented because most of FFT sizes typical for audio take micro- or milliseconds.
But for larger data this would be very reasonable and good to have.
Internally KFR do calculations in 'stages' or passes. Each pass can report when it starts end finishes.
This won't give maximum accuracy but at least it's what is relatively easy to implement.
Could you try to add simple printf before every call to stages[...]->execute here and check if the frequency of printing is enough for your use case:
https://github.com/kfrlib/kfr/blob/master/include/kfr/dft/fft.hpp#L243
If it turns out not to be enough, then precise progress reporting will be much harder to implement without affecting performance in highly optimized pass functions (but still possible).

[meiyasan]

Hi Dan,

I am going to give it a try. It is exactly what I need I think.
Thank you for pointing me out the location.

Cheers, M.