SES Cumulative Weight

Problem

Compute the total weight that simple exponential smoothing puts on the first k observations, counting from the most recent observation backward. The geometric sum equals 1 - (1 - alpha)^k.

Return 0.0 when k is not positive.

Hint

The weights sum to one as k grows without bound.

Test cases

case 1

in: [0.5,2]

expected: 0.75

case 2

in: [0.5,0]

expected: 0

case 3

in: [0.3,3]

expected: 0.657

case 4

in: [1,3]

expected: 1

Starter codePython

def ses_cumulative_weight(alpha, k):
    # Your code here
    pass

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