Tracking Signal

Problem

Compute the tracking signal as the cumulative forecast error divided by the mean absolute deviation: sum(actual - forecast) / mean(abs(actual - forecast)).

Return 0.0 when the MAD is zero or the lists are empty.

Hint

Large absolute tracking signals indicate a biased forecast.

Test cases

case 1

in: [[10,12,14],[11,11,11]]

expected: 1.7999999999999998

case 2

in: [[5,5],[3,7]]

expected: 0

case 3

in: [[1],[1]]

expected: 0

case 4

in: [[1,5,9],[2,2,2]]

expected: 2.4545454545454546

Starter codePython

def tracking_signal(actual, forecast):
    # Your code here
    pass

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