gov.sandia.cognition.learning.function.cost

Class ClusterDistortionMeasure<DataType,ClusterType extends Cluster<DataType>>

java.lang.Object

gov.sandia.cognition.util.AbstractCloneableSerializable

gov.sandia.cognition.learning.function.cost.ClusterDistortionMeasure<DataType,ClusterType>

Type Parameters:

DataType - Type of data to compute the distortion over

ClusterType - Type of clusters to use

All Implemented Interfaces:

Evaluator<java.util.Collection<? extends ClusterType>,java.lang.Double>, CostFunction<java.util.Collection<? extends ClusterType>,ClusterDivergenceFunction<? super ClusterType,? super DataType>>, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

ParallelClusterDistortionMeasure

@PublicationReference(author="Christopher M. Bishop",
                      title="Pattern Recognition and Machine Learning",
                      type=Book,
                      year=2006,
                      pages={424,428},
                      notes="Section 9.1",
                      url="http://research.microsoft.com/~cmbishop/PRML/")
public class ClusterDistortionMeasure<DataType,ClusterType extends Cluster<DataType>>
extends AbstractCloneableSerializable
implements CostFunction<java.util.Collection<? extends ClusterType>,ClusterDivergenceFunction<? super ClusterType,? super DataType>>

Computes the objective measure for a clustering algorithm, based on the internal "distortion" of each cluster. The individual cluster measures are based on a ClusterDivergenceFunction and summed over each cluster.

Since:

3.0

Author:

Kevin R. Dixon

See Also:

ClusterDivergenceFunction, Serialized Form

Constructor Summary

Constructors

Constructor and Description
ClusterDistortionMeasure() Creates a new instance of ClusterDistortionMeasure
ClusterDistortionMeasure(ClusterDivergenceFunction<ClusterType,DataType> costParameters) Creates a new instance of ClusterDistortionMeasure

Method Summary

Modifier and Type	Method and Description
ClusterDistortionMeasure<DataType,ClusterType>	clone() This makes public the clone method on the Object class and removes the exception that it throws.
java.lang.Double	evaluate(ClusterType cluster) Evaluates the distortion for a single cluster
java.lang.Double	evaluate(java.util.Collection<? extends ClusterType> target) Computes the cost of the given target.
ClusterDivergenceFunction<? super ClusterType,? super DataType>	getCostParameters() Gets the parameters of the cost function.
void	setCostParameters(ClusterDivergenceFunction<? super ClusterType,? super DataType> costParameters) Sets the parameters of the cost function used to evaluate the cost of a target.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ClusterDistortionMeasure

public ClusterDistortionMeasure()

Creates a new instance of ClusterDistortionMeasure

ClusterDistortionMeasure

public ClusterDistortionMeasure(ClusterDivergenceFunction<ClusterType,DataType> costParameters)

Creates a new instance of ClusterDistortionMeasure

Parameters:

costParameters - Divergence function that defines the cost function

Method Detail

clone

public ClusterDistortionMeasure<DataType,ClusterType> clone()

Description copied from class: AbstractCloneableSerializable

This makes public the clone method on the Object class and removes the exception that it throws. Its default behavior is to automatically create a clone of the exact type of object that the clone is called on and to copy all primitives but to keep all references, which means it is a shallow copy. Extensions of this class may want to override this method (but call super.clone() to implement a "smart copy". That is, to target the most common use case for creating a copy of the object. Because of the default behavior being a shallow copy, extending classes only need to handle fields that need to have a deeper copy (or those that need to be reset). Some of the methods in ObjectUtil may be helpful in implementing a custom clone method. Note: The contract of this method is that you must use super.clone() as the basis for your implementation.

Specified by:

clone in interface CostFunction<java.util.Collection<? extends ClusterType extends Cluster<DataType>>,ClusterDivergenceFunction<? super ClusterType extends Cluster<DataType>,? super DataType>>

Specified by:

clone in interface CloneableSerializable

Overrides:

clone in class AbstractCloneableSerializable

Returns:

A clone of this object.

evaluate

public java.lang.Double evaluate(java.util.Collection<? extends ClusterType> target)

Description copied from interface: CostFunction

Computes the cost of the given target.

Specified by:

evaluate in interface Evaluator<java.util.Collection<? extends ClusterType extends Cluster<DataType>>,java.lang.Double>

Specified by:

evaluate in interface CostFunction<java.util.Collection<? extends ClusterType extends Cluster<DataType>>,ClusterDivergenceFunction<? super ClusterType extends Cluster<DataType>,? super DataType>>

Parameters:

target - The object to evaluate.

Returns:

The cost of the given object.

evaluate

public java.lang.Double evaluate(ClusterType cluster)

Evaluates the distortion for a single cluster

Parameters:

cluster - Cluster to consider

Returns:

Distortion for a single member

getCostParameters

public ClusterDivergenceFunction<? super ClusterType,? super DataType> getCostParameters()

Description copied from interface: CostFunction

Gets the parameters of the cost function.

Specified by:

getCostParameters in interface CostFunction<java.util.Collection<? extends ClusterType extends Cluster<DataType>>,ClusterDivergenceFunction<? super ClusterType extends Cluster<DataType>,? super DataType>>

Returns:

The current parameters of the cost function.

setCostParameters

public void setCostParameters(ClusterDivergenceFunction<? super ClusterType,? super DataType> costParameters)

Description copied from interface: CostFunction

Sets the parameters of the cost function used to evaluate the cost of a target.

Specified by:

setCostParameters in interface CostFunction<java.util.Collection<? extends ClusterType extends Cluster<DataType>>,ClusterDivergenceFunction<? super ClusterType extends Cluster<DataType>,? super DataType>>

Parameters:

costParameters - The parameters of the cost function.