Computes Kendall's rank correlation coefficient τ for two equal-length
KendallTau[v1, v2]
KendallTau[m]
KendallTau[m1, m2]
KendallTau[dist]
KendallTau[dist, i, j]
KendallTau[{1, 2, 3, 4, 5}, {2, 1, 4, 3, 5}]
→ 3/5KendallTau[{1, 2, 3, 4, 5}, {5, 4, 3, 2, 1}]
→ -1KendallTau[{1, 1, 2, 3}, {1, 2, 2, 3}]
→ 4/5