I am trying to plot magnitude against frequency averaged over a time window.
To do this I make a morlet wavelet Filterbank. And multiply the dft of each kernel by the dft of my incoming data set.
I take the mean value for each kernel multiplication result and plot this.
However somewhere along the way I have lost how to convert this to a meaningful scale.
I am using apple accelerate to perform the FFT, and as this does not scale, I divide each result by the sample size.
When I extract the magnitude using mag = sqrt((real^2) + (imag^2)) I am left with an array of very small numbers.
How do I convert this to meaningful magnitude in dB?