gov.sandia.cognition.learning.algorithm.annealing
Class VectorizablePerturber

java.lang.Object
  extended by gov.sandia.cognition.util.AbstractCloneableSerializable
      extended by gov.sandia.cognition.util.AbstractRandomized
          extended by gov.sandia.cognition.learning.algorithm.annealing.VectorizablePerturber
All Implemented Interfaces:
Perturber<Vectorizable>, CloneableSerializable, Randomized, Serializable, Cloneable

@CodeReviews(reviews={@CodeReview(reviewer="Kevin R. Dixon",date="2008-07-22",changesNeeded=false,comments={"Moved previous code review to annotation.","Fixed a few typos in javadoc.","Code looks fine."}),@CodeReview(reviewer="Justin Basilico",date="2006-10-02",changesNeeded=false,comments="Minor documentation updates.")})
public class VectorizablePerturber
extends AbstractRandomized
implements Perturber<Vectorizable>

The VectorizablePerturber implements a Perturber for Vectorizable objects. It uses an underlying random number generator to perturb each element of the vector.

Since:
1.0
Author:
Justin Basilico, Kevin R. Dixon, Jonathan McClain
See Also:
Serialized Form

Field Summary
 
Fields inherited from class gov.sandia.cognition.util.AbstractRandomized
random
 
Constructor Summary
VectorizablePerturber(Random random, Matrix covariance)
          Creates a new instance of VectorizablePerturber.
 
Method Summary
 VectorizablePerturber clone()
          This makes public the clone method on the Object class and removes the exception that it throws.
 Matrix getCovarianceSqrt()
          Gets the covariance square root matrix.
 Vectorizable perturb(Vectorizable input)
          Perturbs the given Vectorizable by cloning it and then operating on the clone by side-effect.
 Vector perturbVector(Vector input)
          Perturbs the given vector using the underlying random number generator.
 void setCovariance(Matrix covariance)
          Sets the covariance of the perturber.
protected  void setCovarianceSqrt(Matrix covarianceSqrt)
          Sets the covariance square root matrix.
 
Methods inherited from class gov.sandia.cognition.util.AbstractRandomized
getRandom, setRandom
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

VectorizablePerturber

public VectorizablePerturber(Random random,
                             Matrix covariance)
Creates a new instance of VectorizablePerturber. This constructor can take a non-negligible amount of time since it needs to do an eigendecomposition on the covariance matrix in order to calculate its square root.

Parameters:
random - The random number generator to use.
covariance - The covariance matrix to use in perturbing. It must be a symmetric matrix.
Method Detail

clone

public VectorizablePerturber 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 CloneableSerializable
Overrides:
clone in class AbstractRandomized
Returns:
A clone of this object.

perturb

public Vectorizable perturb(Vectorizable input)
Perturbs the given Vectorizable by cloning it and then operating on the clone by side-effect.

Specified by:
perturb in interface Perturber<Vectorizable>
Parameters:
input - The Vectorizable to perturb.
Returns:
The perturbed version of the given vector, which is a new object.

perturbVector

public Vector perturbVector(Vector input)
Perturbs the given vector using the underlying random number generator.

Parameters:
input - The vector to perturb.
Returns:
The perturbed vector using the underlying random number generator.

setCovariance

public void setCovariance(Matrix covariance)
Sets the covariance of the perturber. This calls setCoverianceSqrt on the square root decomposition of the given matrix.

Parameters:
covariance - The covariance matrix.

getCovarianceSqrt

public Matrix getCovarianceSqrt()
Gets the covariance square root matrix.

Returns:
The covariance square root matrix.

setCovarianceSqrt

protected void setCovarianceSqrt(Matrix covarianceSqrt)
Sets the covariance square root matrix.

Parameters:
covarianceSqrt - The new covariance square root matrix.