I would like to roughly estimate the mean amplitude over a frequency range (2-3hz). My impression was that I could transform the data using FFT, and just take the mean of the sub part of the output (absolute values).
However, the input I provide to
numpy.fft.fft is in the range -1.5 to 2.5, while the output (absolute values) are in the range of about 0-6500. Do I need to scale the y-values somehow?
Any other suggestions on how to roughly estimate the mean amplitude of a frequency range?
The problem is that I am doing peak detection and want to discriminate out (as noise) all peaks that are smaller than 10% of the rest of the peaks. The majority of the peaks are expected to have rather equal amplitudes, and it is 10% of this amplitude that all peaks must at least be.