I've succeeded to compute complex FFT of a data array of interleaved values using the arm_cfft_f32() API of the CMSIS DSP library for Cortex-M4, and got in the same array the FFT results as frequency domain values with the same interleaving.
I chose a result value of the Frequency Domain (let say a point) based on a specific criteria, and want to go back to the initial index (in the Time Domain) before calculating the FFT and passing through arm_cfft_radix8by4_f32() API.
Is there anyway to go in the opposite sens, and identify a point based on its FFT result value ?
Thanks and regards, tinymanta.