[ToDo] Add interactivity to playground

[galibhassan]

Data loading

• let the user choose from few different sample data

Statistics

• Mark the mean frequency
• Present standard deviation

@LRydin you said something about RMS and maxima-minima. Could you please elaborate here?

what else?

[LRydin]

Yeah, for the engineers the maxima-minima this is called nadir. So we just have to find abs(min) and abs(max) and then max(abs(min),abs(max)). This only makes sense if you remove the fixed reference frequency of 50/60 Hz.

This brings me to the next important point: We should remove the 50/60 Hz from the data, so that one can compare, on the same plot, recording form Europe (50 Hz) and from the US (60 Hz).

[LRydin]

The other measure is just the integral under the curve, or we can do instead something like sum(abs(freq)). This should tell us roughly the deviation from the ref. (50 or 60 Hz)