https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Intel-mkl-FFT/m-p/1756595#M37646 <P>Is there an efficient way to get the complete frequency domain incl. negative frequencies (yes - I know it's redundant) when doing a real- complex forward FFT?</P><P>Background: I want to perform a Hilbert transform by forward FFT of a signal, setting the obtained negative frequencies to zero and then backward FFTing. The only possibility, I currently see, is to make the original signal complex, but that requires of lot of data copying.</P> Fri, 14 Aug 2026 14:21:52 GMT DD42 2026-08-14T14:21:52Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Intel-mkl-FFT/m-p/1756595#M37646 <P>Is there an efficient way to get the complete frequency domain incl. negative frequencies (yes - I know it's redundant) when doing a real- complex forward FFT?</P><P>Background: I want to perform a Hilbert transform by forward FFT of a signal, setting the obtained negative frequencies to zero and then backward FFTing. The only possibility, I currently see, is to make the original signal complex, but that requires of lot of data copying.</P> Fri, 14 Aug 2026 14:21:52 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Intel-mkl-FFT/m-p/1756595#M37646 DD42 2026-08-14T14:21:52Z