`scipy.cluster.hierarchy._hierarchy_impl:to_tree`

source: build-install/usr/lib/python3.14/site-packages/scipy/cluster/hierarchy/_hierarchy_impl.py:1304

Signature

def to_tree(Z, rd = False)

Summary

Convert a linkage matrix into an easy-to-use tree object.

Extended Summary

The reference to the root ClusterNode object is returned (by default).

Each ClusterNode object has a left, right, dist, id, and count attribute. The left and right attributes point to ClusterNode objects that were combined to generate the cluster. If both are None then the ClusterNode object is a leaf node, its count must be 1, and its distance is meaningless but set to 0.

Note: This function is provided for the convenience of the library user. ClusterNodes are not used as input to any of the functions in this library.

Parameters

Z : ndarray: The linkage matrix in proper form (see the linkage function documentation).
rd : bool, optional: When False (default), a reference to the root ClusterNode object is returned. Otherwise, a tuple (r, d) is returned. r is a reference to the root node while d is a list of ClusterNode objects - one per original entry in the linkage matrix plus entries for all clustering steps. If a cluster id is less than the number of samples n in the data that the linkage matrix describes, then it corresponds to a singleton cluster (leaf node). See linkage for more information on the assignment of cluster ids to clusters.

Returns

tree : ClusterNode or tuple (ClusterNode, list of ClusterNode): If rd is False, a ClusterNode. If rd is True, a list of length 2*n - 1, with n the number of samples. See the description of rd above for more details.

Examples

import numpy as np
from scipy.cluster import hierarchy
rng = np.random.default_rng()
x = rng.random((5, 2))
Z = hierarchy.linkage(x)

✓

hierarchy.to_tree(Z)

✗

<scipy.cluster.hierarchy._hierarchy_impl.ClusterNode object at 0x7f3f434647c0>

rootnode, nodelist = hierarchy.to_tree(Z, rd=True)

✓

rootnode

✗

<scipy.cluster.hierarchy._hierarchy_impl.ClusterNode object at 0x7f3f43464e50>

len(nodelist)

✓

Aliases

scipy.cluster.hierarchy.to_tree