def distance_submatrix(self, dist_mat):
r"""Extract matrix of distances between leafs under the node.
Parameters
----------
dist_mat: numpy.ndarray
Distance matrix (square or in condensed form) among all N leaves
of the tree to which the node belongs to. The row indexes of
`dist_mat` must correspond to the node IDs of the leaves.
Returns
-------
:class:`~numpy:numpy.ndarray`
square distance matrix MxM between the M leafs under the node
"""
return distance_submatrix(dist_mat, self.leaf_ids)
def test_distance_submatrix():
a = np.arange(4)
dist_mat = np.square(a - a[:, np.newaxis])
submatrix = idpd.distance_submatrix(dist_mat, [1, 3])
reference = np.array([[0, 4], [4, 0]])
assert_allclose(submatrix, reference, atol=0.001)