Kendall's Tau-b

Problem

Return Kendall's tau-b (P - Q)/sqrt((P+Q+Tx)(P+Q+Ty)) with tie corrections, where Tx counts pairs tied on x only and Ty pairs tied on y only. Return 0.0 when there are fewer than two pairs or the denominator is zero.

Hint

Tau-b adjusts for ties in either variable.

Test cases

case 1

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

expected: 1

case 2

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

expected: -1

case 3

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

expected: 0.9128709291752769

case 4

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

expected: 0.5

case 5

in: [[1],[1]]

expected: 0

Starter codePython

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

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