scipy tutorial - Baustatik-Info-Server

Parameters
y
Returns
Z
SciPy Reference Guide, Release 0.8.dev
[ndarray] The upper triangular of the distance matrix. The result of pdist is returned in
this form.
[ndarray] A linkage matrix containing the hierarchical clustering. See the linkage function
documentation for more information on its structure.
cophenet(Z, Y=None)
Calculates the cophenetic distances between each observation in the hierarchical clustering defined by the
linkage Z.
Suppose p and q are original observations in disjoint clusters s and t, respectively and s and t are joined by
a direct parent cluster u. The cophenetic distance between observations i and j is simply the distance between
clusters s and t.
Parameters
• Z : ndarray The hierarchical clustering encoded as an array (see linkage function).
• Y : ndarray (optional) Calculates the cophenetic correlation coefficient c of a hierarchical
clustering defined by the linkage matrix Z of a set of n observations in m dimensions. Y is
the condensed distance matrix from which Z was generated.
Returns
(c, {d}) - c : ndarray
The cophentic correlation distance (if y is passed).
• d : ndarray The cophenetic distance matrix in condensed form. The ij th entry is the cophenetic
distance between original observations i and j.
correspond(Z, Y)
Checks if a linkage matrix Z and condensed distance matrix Y could possibly correspond to one another.
They must have the same number of original observations for the check to succeed.
This function is useful as a sanity check in algorithms that make extensive use of linkage and distance matrices
that must correspond to the same set of original observations.
Arguments
Returns
• Z
[ndarray] The linkage matrix to check for correspondance.
• Y
[ndarray] The condensed distance matrix to check for correspondance.
• b
[bool] A boolean indicating whether the linkage matrix and distance matrix could possibly
correspond to one another.
3.1. Clustering package (scipy.cluster) 133