Kendall's Tau measures the correlation between ordinal rankings. This
implementation is similar to the one used in scipy.stats.kendalltau.
The provided values may be of any type that is sortable, with the
argsort indices indicating the true or proposed ordinal sequence.
a Tensor of shape [n] containing the true ordinal ranking.
a Tensor of shape [n] containing the predicted ordering of the
same N items.
Optional Python str name for ops created by this method.
Default value: None (i.e., 'kendalls_tau').
Kendall's Tau, the 1945 tau-b formulation that ignores
ordering of ties, as a float32 scalar Tensor.