Wavelet Energy Share

Problem

Compute the share of signal energy carried by the first-level Haar detail coefficients. Split the series into consecutive pairs; each pair gives approximation (a + b)/sqrt(2) and detail (b - a)/sqrt(2).

Return the detail energy divided by the total energy of both coefficient types, or 0.0 when total energy is zero or the series has fewer than two points.

Hint

A high detail share means the series changes quickly at the finest scale.

Test cases

case 1

in: [[1,2,3,4]]

expected: 0.033333333333333326

case 2

in: [[1,1,1,1]]

expected: 0

case 3

in: [[1,0,1,0]]

expected: 0.5

case 4

in: [[2,2,2,3]]

expected: 0.023809523809523808

Starter codePython

def wavelet_energy_share(series):
    # Your code here
    pass

4 test cases · run your code against them in the editor