maxRstat — SciPy v1.15.2 Manual (original) (raw)

scipy.cluster.hierarchy.

scipy.cluster.hierarchy.maxRstat(Z, R, i)[source]#

Return the maximum statistic for each non-singleton cluster and its children.

Parameters:

Zarray_like

The hierarchical clustering encoded as a matrix. See linkage for more information.

Rarray_like

The inconsistency matrix.

iint

The column of R to use as the statistic.

Returns:

MRndarray

Calculates the maximum statistic for the i’th column of the inconsistency matrix R for each non-singleton cluster node. MR[j] is the maximum over R[Q(j)-n, i], whereQ(j) the set of all node ids corresponding to nodes below and including j.

See also

linkage

for a description of what a linkage matrix is.

inconsistent

for the creation of a inconsistency matrix.

Examples

from scipy.cluster.hierarchy import median, inconsistent, maxRstat from scipy.spatial.distance import pdist

Given a data set X, we can apply a clustering method to obtain a linkage matrix Z. scipy.cluster.hierarchy.inconsistent can be also used to obtain the inconsistency matrix R associated to this clustering process:

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 = median(pdist(X)) R = inconsistent(Z) R array([[1. , 0. , 1. , 0. ], [1. , 0. , 1. , 0. ], [1. , 0. , 1. , 0. ], [1. , 0. , 1. , 0. ], [1.05901699, 0.08346263, 2. , 0.70710678], [1.05901699, 0.08346263, 2. , 0.70710678], [1.05901699, 0.08346263, 2. , 0.70710678], [1.05901699, 0.08346263, 2. , 0.70710678], [1.74535599, 1.08655358, 3. , 1.15470054], [1.91202266, 1.37522872, 3. , 1.15470054], [3.25 , 0.25 , 3. , 0. ]])

scipy.cluster.hierarchy.maxRstat can be used to compute the maximum value of each column of R, for each non-singleton cluster and its children:

maxRstat(Z, R, 0) array([1. , 1. , 1. , 1. , 1.05901699, 1.05901699, 1.05901699, 1.05901699, 1.74535599, 1.91202266, 3.25 ]) maxRstat(Z, R, 1) array([0. , 0. , 0. , 0. , 0.08346263, 0.08346263, 0.08346263, 0.08346263, 1.08655358, 1.37522872, 1.37522872]) maxRstat(Z, R, 3) array([0. , 0. , 0. , 0. , 0.70710678, 0.70710678, 0.70710678, 0.70710678, 1.15470054, 1.15470054, 1.15470054])