topic Re: Re:Trigonometric Transforms in Intel® oneAPI Math Kernel Library

Trigonometric Transforms

JakubV — Fri, 03 Feb 2023 14:20:01 GMT

Hello,

does anyone know, where I can find the exact mathematical formulas, that are implemented in MKL subroutines for the trigonometric transforms (part of PDE support)? Including index ranges and normalization factors. Thanks.

Trigonometric Transforms Implemented

JakubV

Re:Trigonometric Transforms

VidyalathaB_Intel — Mon, 06 Feb 2023 16:47:00 GMT

Hi Jakub,

Thanks for reaching out to us.

Could you please let us know your use case here? Please elaborate on your issue and requirement for mathematical formulas that are implemented in MKL subroutines.

Regards,

Vidya.

Re: Re:Trigonometric Transforms

JakubV — Mon, 06 Feb 2023 17:01:35 GMT

Dear Vidya,

thank you for looking into that.

What I'd like to see is an equivalent of the formula that you specify for the Fourier Transform Functions

at the beginning of this page.

That is, what exact sums are calculated by the Forward/Backward Cosine/Sine Unstaggered/Staggered/Staggered2

MKL routines, and how are they related to DCT-I, DCT-II, DCT-III, and DCT-IV from Rao 1990?

Rao, K.R. and Yip, P. Discrete Cosine Transform. Algorithms, Advantages, Applications. Academic Press Inc., 1990.

My case is simple, I want to use the DCT for fast Chebyshev approximation calculation.

Best regards,

Jakub

Re: Re:Trigonometric Transforms

JakubV — Tue, 07 Feb 2023 07:57:25 GMT

I can see now, that the Trigonometric Transforms Implemented page has just been updated!

That is exactly what I needed. Thank you, Intel, for a prompt reaction.

Jakub

Re:Trigonometric Transforms

VidyalathaB_Intel — Wed, 08 Feb 2023 02:41:06 GMT

Hi Jakub,

As the issue is resolved we are closing this thread. Please post a new question if you need any additional assistance from Intel as this thread will no longer be monitored.

Regards,

Vidya.