`scipy.cluster.hierarchy:leaves_list`

source: /scipy/cluster/hierarchy.py :2806

Signature

def leaves_list ( Z )

Summary

Return a list of leaf node ids.

Extended Summary

The return corresponds to the observation vector index as it appears in the tree from left to right. Z is a linkage matrix.

Parameters

Z : ndarray: The hierarchical clustering encoded as a matrix. Z is a linkage matrix. See linkage for more information.

Returns

leaves_list : ndarray: The list of leaf node ids.

Notes

Array API Standard Support

leaves_list has experimental support for Python Array API Standard compatible backends in addition to NumPy. Please consider testing these features by setting an environment variable SCIPY_ARRAY_API=1 and providing CuPy, PyTorch, JAX, or Dask arrays as array arguments. The following combinations of backend and device (or other capability) are supported.

====================  ====================  ====================
Library               CPU                   GPU
====================  ====================  ====================
NumPy                 ✅                     n/a                 
CuPy                  n/a                   ⛔                   
PyTorch               ✅                     ⛔                   
JAX                   ✅                     ⛔                   
Dask                  ⚠️ merges chunks      n/a                 
====================  ====================  ====================

See dev-arrayapi for more information.

Examples

from scipy.cluster.hierarchy import ward, dendrogram, leaves_list
from scipy.spatial.distance import pdist
from matplotlib import pyplot as plt

✓

X = [[0, 0], [0, 1], [1, 0],
     [0, 4], [0, 3], [1, 4],
     [4, 0], [3, 0], [4, 1],
     [4, 4], [3, 4], [4, 3]]

✓

Z = ward(pdist(X))

✓

The linkage matrix ``Z`` represents a dendrogram, that is, a tree that encodes the structure of the clustering performed. `scipy.cluster.hierarchy.leaves_list` shows the mapping between indices in the ``X`` dataset and leaves in the dendrogram:

leaves_list(Z)

✓

fig = plt.figure(figsize=(25, 10))
dn = dendrogram(Z)
plt.show()

✓

Aliases

scipy.cluster.hierarchy.leaves_list