Spearman Rank Correlation with Ties

Problem

Return the Spearman rank correlation between x and y, using average ranks for tied values and then the Pearson formula on the ranks. Return 0.0 when fewer than two pairs are given or either rank vector is constant.

Hint

Rank both lists with average ranks for ties, then correlate the ranks.

Test cases

case 1

in: [[1,2,3,4],[1,4,9,16]]

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: 0.9486832980505138

case 4

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

expected: 0

case 5

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

expected: 0.6

Starter codePython

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

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