MKL FFT returns bins with 0 value.

pedro-erencia — Tue, 06 Jul 2021 14:00:12 GMT

I'm running an FFT with mkl ComputeForward and sometimes, some of the bins are 0 + 0i.

Specifically, If I do a single, in place DFT of 20480 samples of a single 16K tone sampled at

1.024 MSps, all the bins have values except just one, which is zero. Curiously, the surrounding

bins seem ok.

...

-2.13270645e-13 -6.73710165e-13

-2.29536984e-13 -1.78759893e-12

0.00000000 0.00000000

-2.29536957e-13 1.78759893e-12

-2.13270550e-13 6.73710274e-13

-3.53691855e-14 2.86772993e-13

....

What can be causing this? I don't think it is a resolution problem because the failing bin should

fit in a float, I checked it doing the FFT with Octave.

topic MKL FFT returns bins with 0 value. in Intel® oneAPI Math Kernel Library