Cobweb

Package

weka.clusterers

Synopsis

Class implementing the Cobweb and Classit clustering algorithms.

Note: the application of node operators (merging, splitting etc.) in terms of ordering and priority differs (and is somewhat ambiguous) between the original Cobweb and Classit papers. This algorithm always compares the best host, adding a new leaf, merging the two best hosts, and splitting the best host when considering where to place a new instance.

For more information see:

D. Fisher (1987). Knowledge acquisition via incremental conceptual clustering. Machine Learning. 2(2):139-172.

J. H. Gennari, P. Langley, D. Fisher (1990). Models of incremental concept formation. Artificial Intelligence. 40:11-61.

Options

The table below describes the options available for Cobweb.

Option

Description

acuity

set the minimum standard deviation for numeric attributes

cutoff

set the category utility threshold by which to prune nodes

saveInstanceData

save instance information for visualization purposes

seed

The random number seed to be used.

Capabilities

The table below describes the capabilites of Cobweb.

Capability

Supported

Class

No class

Attributes

Missing values, Nominal attributes, Unary attributes, Binary attributes, Empty nominal attributes, Date attributes, Numeric attributes

Min # of instances

0