MKL FFT returns bins with 0 value.

Intel® oneAPI Math Kernel Library

Ask questions and share information with other developers who use Intel® Math Kernel Library.

MKL FFT returns bins with 0 value.

558 Views

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.

Link Copied

0 Replies

Community support is provided Monday to Friday. Other contact methods are available here.

Intel does not verify all solutions, including but not limited to any file transfers that may appear in this community. Accordingly, Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

For more complete information about compiler optimizations, see our Optimization Notice.