gov.sandia.cognition.learning.algorithm.root

Class RootBracketExpander

java.lang.Object

gov.sandia.cognition.util.AbstractCloneableSerializable

gov.sandia.cognition.algorithm.AbstractIterativeAlgorithm

gov.sandia.cognition.algorithm.AbstractAnytimeAlgorithm<ResultType>

gov.sandia.cognition.learning.algorithm.AbstractAnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>

gov.sandia.cognition.learning.algorithm.root.RootBracketExpander

All Implemented Interfaces:

AnytimeAlgorithm<LineBracket>, IterativeAlgorithm, StoppableAlgorithm, AnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>, BatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>, RootBracketer, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

public class RootBracketExpander
extends AbstractAnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>
implements RootBracketer

The root-bracketing expansion algorithm. This function repeatedly expands a root bracket about an initial guess until it finds a region where it can be demonstrated that the function makes a zero-crossing (root). The algorithm can fail on functions where the function "kisses" zero, or has a "notch" type look.

Since:

3.0

Author:

Kevin R. Dixon

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_INITIAL_GUESS Default initial guess, 0.0
static int	DEFAULT_MAX_ITERATIONS Default max iterations, 100
static double	SCALE_FACTOR Default scale factor on expansion, the golden ratio, 1.618034

Fields inherited from class gov.sandia.cognition.learning.algorithm.AbstractAnytimeBatchLearner

data, keepGoing

Fields inherited from class gov.sandia.cognition.algorithm.AbstractAnytimeAlgorithm

maxIterations

Fields inherited from class gov.sandia.cognition.algorithm.AbstractIterativeAlgorithm

DEFAULT_ITERATION, iteration

Constructor Summary

Constructors

Constructor and Description
RootBracketExpander() Creates a new instance of RootBracketExpander

Method Summary

Modifier and Type	Method and Description
protected void	cleanupAlgorithm() Called to clean up the learning algorithm's state after learning has finished.
LineBracket	getBracket() Getter for bracket.
double	getInitialGuess() Getter for initialGuess.
LineBracket	getResult() Gets the current result of the algorithm.
protected boolean	initializeAlgorithm() Called to initialize the learning algorithm's state based on the data that is stored in the data field.
boolean	isResultValid() Indicates whether or not the algorithm results are in a consistent state or not.
protected void	setBracket(LineBracket bracket) Setter for bracket.
void	setInitialGuess(double initialGuess) Sets the initial guess of the root location.
protected boolean	step() Called to take a single step of the learning algorithm.

Methods inherited from class gov.sandia.cognition.learning.algorithm.AbstractAnytimeBatchLearner

clone, getData, getKeepGoing, learn, setData, setKeepGoing, stop

Methods inherited from class gov.sandia.cognition.algorithm.AbstractAnytimeAlgorithm

getMaxIterations, setMaxIterations

Methods inherited from class gov.sandia.cognition.algorithm.AbstractIterativeAlgorithm

addIterativeAlgorithmListener, fireAlgorithmEnded, fireAlgorithmStarted, fireStepEnded, fireStepStarted, getIteration, getListeners, removeIterativeAlgorithmListener, setIteration, setListeners

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.sandia.cognition.learning.algorithm.BatchLearner

learn

Methods inherited from interface gov.sandia.cognition.util.CloneableSerializable

clone

Methods inherited from interface gov.sandia.cognition.algorithm.AnytimeAlgorithm

getMaxIterations, setMaxIterations

Methods inherited from interface gov.sandia.cognition.algorithm.IterativeAlgorithm

addIterativeAlgorithmListener, getIteration, removeIterativeAlgorithmListener

Methods inherited from interface gov.sandia.cognition.algorithm.StoppableAlgorithm

stop

Field Detail

SCALE_FACTOR

public static final double SCALE_FACTOR

Default scale factor on expansion, the golden ratio, 1.618034

See Also:

Constant Field Values

DEFAULT_MAX_ITERATIONS

public static final int DEFAULT_MAX_ITERATIONS

Default max iterations, 100

See Also:

Constant Field Values

DEFAULT_INITIAL_GUESS

public static final double DEFAULT_INITIAL_GUESS

Default initial guess, 0.0

See Also:

Constant Field Values

Constructor Detail

RootBracketExpander

public RootBracketExpander()

Creates a new instance of RootBracketExpander

Method Detail

initializeAlgorithm

protected boolean initializeAlgorithm()

Description copied from class: AbstractAnytimeBatchLearner

Called to initialize the learning algorithm's state based on the data that is stored in the data field. The return value indicates if the algorithm can be run or not based on the initialization.

Specified by:

initializeAlgorithm in class AbstractAnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>

Returns:

True if the learning algorithm can be run and false if it cannot.

step

protected boolean step()

Description copied from class: AbstractAnytimeBatchLearner

Called to take a single step of the learning algorithm.

Specified by:

step in class AbstractAnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>

Returns:

True if another step can be taken and false it the algorithm should halt.

cleanupAlgorithm

protected void cleanupAlgorithm()

Description copied from class: AbstractAnytimeBatchLearner

Called to clean up the learning algorithm's state after learning has finished.

Specified by:

cleanupAlgorithm in class AbstractAnytimeBatchLearner<Evaluator<java.lang.Double,java.lang.Double>,LineBracket>

getResult

public LineBracket getResult()

Description copied from interface: AnytimeAlgorithm

Gets the current result of the algorithm.

Specified by:

getResult in interface AnytimeAlgorithm<LineBracket>

Returns:

Current result of the algorithm.

isResultValid

public boolean isResultValid()

Description copied from interface: StoppableAlgorithm

Indicates whether or not the algorithm results are in a consistent state or not. A StoppableAlgorithm may not always be able to stop in a manner that makes its results valid. This method is used to check whether the results are in a consistent state or not.

Specified by:

isResultValid in interface StoppableAlgorithm

Overrides:

isResultValid in class AbstractAnytimeAlgorithm<LineBracket>

Returns:

True if the results of the algorithm are in valid state and false if they are not valid.

getInitialGuess

public double getInitialGuess()

Getter for initialGuess.

Returns:

Initial guess of the root's location.

setInitialGuess

public void setInitialGuess(double initialGuess)

Description copied from interface: RootBracketer

Sets the initial guess of the root location.

Specified by:

setInitialGuess in interface RootBracketer

Parameters:

initialGuess - Initial guess of the root location.

getBracket

public LineBracket getBracket()

Getter for bracket.

Returns:

Bracket on the root location.

setBracket

protected void setBracket(LineBracket bracket)

Setter for bracket.

Parameters:

bracket - Bracket on the root location.