Glass's Delta

Problem

Return Glass's delta (mean_x - mean_y) / s_y, standardizing by the sample standard deviation of the second group only. Return 0.0 when x is empty, y has fewer than two values, or s_y is zero.

Hint

Using the control SD avoids contamination by the treatment.

Test cases

case 1

in: [[1,2,3,4,5],[2,4,6,8,10]]

expected: -0.9486832980505138

case 2

in: [[10,12,14],[9,11,13]]

expected: 0.5

case 3

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

expected: 0

case 4

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

expected: 2.1213203435596424

case 5

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

expected: -2.1213203435596424

Starter codePython

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

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