Problem with DftiComputeForward call

tdot — Tue, 09 Jan 2024 16:58:26 GMT

Using an input data set of std::complex<double> sig2[3]={{0.6,0.5},{0.4,0.3},{0, 0.1}};

The call to status = DftiComputeForward(my_desc1_handle, sig2) results in

sig2 = {{2969.6, 2.046384154832482e-13i}, {2.0463846969335625e-13 , 0.3}, {0, 0.1}}.

A call to Matlab fft(sig2) results in sig2 = {{1.2, 0.9},{0.4732, 0.1268}, { 0.1268, 0.4732}}

The two don't agree and I place more confidence in the Matlab result at this point. The code I am using is copied from the example provided by the library documentation. Below is that code.

DFTI_DESCRIPTOR_HANDLE my_desc1_handle = nullptr;
MKL_LONG status;
std::complex<double> sig2[3]={{0.6,0.5},{0.4,0.3},{0, 0.1}};
status = DftiCreateDescriptor(&my_desc1_handle, DFTI_SINGLE, DFTI_COMPLEX, 1, 3);

status = DftiCommitDescriptor(my_desc1_handle);
status = DftiComputeForward(my_desc1_handle, sig2);

Note all status result l have been check for each step, I ahve not included them. Using debug stepping I have verified that status has been 0 for each call.

device info: [Intel(R) Corporation Intel(R) Xeon(R) Gold 5218R CPU @ 2.10GHz Version: 3.0]

Running on Linux5.4.17 x86_64

Mkl installed version is 2023.0.0

topic Problem with DftiComputeForward call in Intel® oneAPI Math Kernel Library

Problem with DftiComputeForward call