SES One-Step Forecast

Problem

Return the one-step-ahead forecast produced by simple exponential smoothing, which is the final level after processing the whole series: s[t] = alpha * x[t] + (1 - alpha) * s[t-1] with s[0] = x[0].

Return 0.0 for an empty series.

Hint

No recursion needed: just fold the series into a single running level.

Test cases

case 1

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

expected: 3.125

case 2

in: [[5,5,5],0.3]

expected: 5

case 3

in: [[10],0.7]

expected: 10

case 4

in: [[2,4,6],1]

expected: 6

Starter codePython

def ses_forecast(series, alpha):
    # Your code here
    pass

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