Find large number of consecutive values fulfilling condition in a numpy array

Question

I have some audio data loaded in a numpy array and I wish to segment the data by finding silent parts, i.e. parts where the audio amplitude is below a certain threshold over

Answer 1

There is a very convenient solution to this using scipy.ndimage. For an array:

a = array([1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0])

which can be the result of a condition applied to another array, finding the contiguous regions is as simple as:

regions = scipy.ndimage.find_objects(scipy.ndimage.label(a)[0])

Then, applying any function to those regions can be done e.g. like:

[np.sum(a[r]) for r in regions]