Weighted Moving Average

Problem

Compute a weighted moving average where weights[0] applies to the most recent value of each window. For the window ending at index i the output is sum(weights[j] * x[i-j]) / sum(weights).

Return an empty list if weights is empty, longer than the series, or sums to zero. The output length is len(series) - len(weights) + 1.

Hint

Reverse the window when pairing it with the newest-first weights.

Test cases

case 1

in: [[1,2,3,4],[0.5,0.5]]

expected: [1.5,2.5,3.5]

case 2

in: [[10,20,30],[1,3]]

expected: [12.5,22.5]

case 3

in: [[5],[2]]

expected: [5]

case 4

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

expected: []

Starter codePython

def weighted_moving_average(series, weights):
    # Your code here
    pass

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