topic Hi, all: in Intel® oneAPI Math Kernel Library

Intel MKL DFT gives incorrect result on odd number sampling points

Jianhua_J_ — Fri, 07 Jul 2017 15:15:07 GMT

HI, all:

I'm using MKL DFTI to do 2D complex in-place DFTs. I found that when the size of my data array is odd, say 89x89 or 45x45, DFT results are incorrect while when the size of my data array is even say 48x48 or 80x80, DFT results are correct. I read the MKL manual, it says that MKL supports arbitrary size of DFTs. I wonder what could cause this odd/even problem. I appreciate any help or hint.

Thanks,

Jianhua

you may take a look at the

Gennady_F_Intel — Sun, 09 Jul 2017 18:17:49 GMT

you may take a look at the one of 2D FFT examples we have in mkl package ( <mklroot>\examples\dftc\source ). for example - basic_dp_complex_dft_2d.c - this example - complex-to-complex in-place 2D with odd problem sizes ( n1=7, n2=11).

Hi, all:

Jianhua_J_ — Mon, 17 Jul 2017 17:51:40 GMT

Hi, all:

Thanks for all the comments and replies. I finally found the problem. It is in my implementation of ifftshift of matlab function. I wish that Intel MKL have such commonly used DFT utility function, which could save me days of work.

Jianhua