Scipy/Numpy FFT Frequency Analysis

Question

I\'m looking for how to turn the frequency axis in a fft (taken via scipy.fftpack.fftfreq) into a frequency in Hertz, rather than bins or fractional bins.

I tried to

Answer 1

The frequency width of each bin is (sampling_freq / num_bins).

A more fundamental problem is that your sample rate is not sufficient for your signals of interest. Your sample rate is 8.3 Hz; you need at least 16Hz in order to capture an 8Hz input tone.¹

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_{1. To all the DSP experts; I'm aware that it's actually BW that's relevant, not max frequency. But I'm assuming the OP doesn't want to do undersampled data acquisition.}