topic Bo, in IntelĀ® oneAPI Math Kernel Library & IntelĀ® Math Kernel Library
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005800#M18874
<P>Bo,<BR />
I think you are talking the dpar/spar parameter for these functions. Actually, they are not used for the computed result. They are just used for store the intermediate sin/cos data that are used in the TT computation.</P>
<P>For the computation function:<BR />
d_forward_trig_transform(double f[], DFTI_DESCRIPTOR_HANDLE *handle, MKL_INT ipar[], double dpar[], MKL_INT *stat);</P>
<P>Both the input and output is F[], which is the same size.</P>
<P>Thanks<BR />
Chao</P>
<P> </P>
<P> </P>
<P> </P>Thu, 24 Jul 2014 03:11:06 GMTChao_Y_Intel2014-07-24T03:11:06Zoutput length of cosine transform
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005797#M18871
<P>I have a seemingly naive question: why the length of the output of cosine transform might be longer than n? For example, for staggered cosine transform, the output length is 3n/2. But just looking at its equation, the output should have the same length as the input, which is n. Thanks!</P>
<P>Bo</P>Mon, 21 Jul 2014 16:03:50 GMThttps://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005797#M18871Bo_Q_2014-07-21T16:03:50ZBo,
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005798#M18872
<P>Bo,</P>
<P>Are you talking to some specific MKL questions, or this just a general question regarding the DCT transform?</P>
<P>Thanks,<BR />
Chao</P>Tue, 22 Jul 2014 02:11:55 GMThttps://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005798#M18872Chao_Y_Intel2014-07-22T02:11:55ZThanks for your reply. I am
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005799#M18873
<P>Thanks for your reply. I am only interested in using DCT but the question is applicable to sine transforms as well. Here are the defination of the transforms:</P>
<P><A href="https://software.intel.com/sites/products/documentation/hpc/mkl/mklman/GUID-48C88175-7E59-46C7-99E1-A78BCEE0E981.htm" target="_blank">https://software.intel.com/sites/products/documentation/hpc/mkl/mklman/GUID-48C88175-7E59-46C7-99E1-A78BCEE0E981.htm</A></P>
<P>For instance, for the staggered cosine transform, its output is F(k) with k = 0...n-1, that is n elements in total. But if you look at the documentation here:</P>
<P><A href="https://software.intel.com/sites/products/documentation/hpc/mkl/mklman/GUID-3DA88A75-AC3D-45F1-B647-7D020451D010.htm" target="_blank">https://software.intel.com/sites/products/documentation/hpc/mkl/mklman/GUID-3DA88A75-AC3D-45F1-B647-7D020451D010.htm</A></P>
<P>You will find the output has 3n/2 elements. Why?</P>
<P> </P>
<P>Bo</P>
<P> </P>Tue, 22 Jul 2014 02:37:30 GMThttps://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005799#M18873Bo_Q_2014-07-22T02:37:30ZBo,
https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005800#M18874
<P>Bo,<BR />
I think you are talking the dpar/spar parameter for these functions. Actually, they are not used for the computed result. They are just used for store the intermediate sin/cos data that are used in the TT computation.</P>
<P>For the computation function:<BR />
d_forward_trig_transform(double f[], DFTI_DESCRIPTOR_HANDLE *handle, MKL_INT ipar[], double dpar[], MKL_INT *stat);</P>
<P>Both the input and output is F[], which is the same size.</P>
<P>Thanks<BR />
Chao</P>
<P> </P>
<P> </P>
<P> </P>Thu, 24 Jul 2014 03:11:06 GMThttps://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/output-length-of-cosine-transform/m-p/1005800#M18874Chao_Y_Intel2014-07-24T03:11:06Z