xal.extension.solver.algorithm

Class RandomShrinkSearch.RandomSearcher

java.lang.Object

xal.extension.solver.algorithm.RandomShrinkSearch.RandomSearcher

All Implemented Interfaces:

RandomShrinkSearch.Searcher

Direct Known Subclasses:

RandomShrinkSearch.ComboSearcher, RandomShrinkSearch.ShrinkSearcher

Enclosing class:

RandomShrinkSearch

protected class RandomShrinkSearch.RandomSearcher
extends java.lang.Object
implements RandomShrinkSearch.Searcher

A searcher that performs a simple random search in the entire search space.

Field Summary

Fields

Modifier and Type	Field and Description
protected double	_changeProbabilityBase Description of the Field
protected java.util.Random	_randomGenerator Description of the Field
protected java.util.Map<Variable,java.lang.Number>	_values Map of values keyed by variable
protected int	NUM_VARIABLES Description of the Field

Constructor Summary

Constructors

Constructor and Description
RandomSearcher() Constructor

Method Summary

Modifier and Type	Method and Description
void	newTopSolution(TrialPoint oldPoint, TrialPoint newPoint) An event indicating that a new solution has been found which is better than the previous best solution according to the score given by the evaluator.
TrialPoint	nextPoint() Get the next trial point.
TrialPoint	nextPoint(int expectedNumToChange) Get the next trial point given the expected number of variables to change.
TrialPoint	nextTrialPoint() Get the next trial point.
protected double	proposeValue(Variable variable) Propose a new value for the variable by selecting a random value in the variable's search range.
void	reset() reset for searching from scratch; forget history

Methods inherited from class java.lang.Object

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

Field Detail

NUM_VARIABLES

protected final int NUM_VARIABLES

Description of the Field

_randomGenerator

protected java.util.Random _randomGenerator

Description of the Field

_changeProbabilityBase

protected double _changeProbabilityBase

Description of the Field

_values

protected java.util.Map<Variable,java.lang.Number> _values

Map of values keyed by variable

Constructor Detail

RandomSearcher

public RandomSearcher()

Constructor

Method Detail

reset

public void reset()

reset for searching from scratch; forget history

Specified by:

reset in interface RandomShrinkSearch.Searcher

newTopSolution

public void newTopSolution(TrialPoint oldPoint,
                           TrialPoint newPoint)

An event indicating that a new solution has been found which is better than the previous best solution according to the score given by the evaluator.

Specified by:

newTopSolution in interface RandomShrinkSearch.Searcher

Parameters:

oldPoint - The old best point.

newPoint - The new best point.

nextTrialPoint

public TrialPoint nextTrialPoint()

Get the next trial point. Simply returns nextPoint().

Specified by:

nextTrialPoint in interface RandomShrinkSearch.Searcher

Returns:

the next trial point.

nextPoint

public TrialPoint nextPoint()

Get the next trial point.

Returns:

the next trial point.

nextPoint

public TrialPoint nextPoint(int expectedNumToChange)

Get the next trial point given the expected number of variables to change. Randomly pick the number of variables to vary by weighing it based on the average number we expect to vary. If no variables get selected to change then we pick the number of variables to change randomly from 1 to the total number of variables available. For each variable that was selected to change, we randomly select a value within the target domain for the variable.

Parameters:

expectedNumToChange - The average number of variables that we expect to change.

Returns:

the next trial point.

proposeValue

protected double proposeValue(Variable variable)

Propose a new value for the variable by selecting a random value in the variable's search range.

Parameters:

variable - the variable for which to propose a new value

Returns:

the new value to propose for the variable