DTW Distance Small

Problem

Compute the dynamic time warping distance between two series using absolute difference cost and the recurrence D[i][j] = |x[i-1] - y[j-1]| + min(D[i-1][j], D[i][j-1], D[i-1][j-1]).

Return the final accumulated cost, or 0.0 if either series is empty.

Hint

DTW can stretch or compress the time axis, so warped series still match cheaply.

Test cases

case 1

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

expected: 0

case 2

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

expected: 2

case 3

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

expected: 1

case 4

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

expected: 1

Starter codePython

def dtw_distance(x, y):
    # Your code here
    pass

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