Expanding Window Mean Forecast

Problem

Compute expanding-window mean forecasts: for each time step t from initial to n-1, forecast the mean of values[0:t].

Return [] if initial < 1 or initial >= n.

Hint

Each forecast uses only the data available before the predicted time step.

case 1

in: [[1,2,3,4,5],3]

expected: [2,2.5]

case 2

in: [[10,20],1]

expected: [10]

case 3

in: [[1,2],2]

expected: []

case 4

in: [[1,2],0]

expected: []

Starter codePython

def expanding_window_mean_forecast(values, initial):
    # Your code here
    pass

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