org.cpsolver.ifs.heuristics

Class StandardNeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>

java.lang.Object

org.cpsolver.ifs.heuristics.StandardNeighbourSelection<V,T>

Type Parameters:

V - Variable

T - Value

All Implemented Interfaces:

NeighbourSelection<V,T>

Direct Known Subclasses:

BacktrackNeighbourSelection, NeighbourSelectionWithSuggestions, RoundRobinNeighbourSelection

public class StandardNeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>
extends Object
implements NeighbourSelection<V,T>

Standard neighbour selection criterion.

This criterion is using the provided variable and value selection criteria. In each step, a variable is selected first using the VariableSelection. Then, a value is selected to the selected variable, using the ValueSelection. A SimpleNeighbour containing the selected value is returned.

Note: the use of neighbour select criteria extends the former implementation of the IFS algorithm which was only able to use variable and value selection criteria and therefore only one value was assigned in each iteration.

Parameters:

Related Solver Parameters

Parameter	Type	Comment
Value.Class	String	Fully qualified class name of the value selection criterion (see ValueSelection, e.g. GeneralValueSelection)
Variable.Class	String	Fully qualified class name of the variable selection criterion (see VariableSelection, e.g. GeneralVariableSelection)

Version:

IFS 1.3 (Iterative Forward Search)
Copyright (C) 2006 - 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses.

Author:

Tomáš Müller

See Also:

Solver

Field Summary

Fields

Modifier and Type	Field and Description
protected Solver<V,T>	iSolver
protected ConflictStatistics<V,T>	iStat
protected static org.apache.logging.log4j.Logger	sLogger

Constructor Summary

Constructors

Constructor and Description
StandardNeighbourSelection(DataProperties properties) Constructor

Method Summary

Modifier and Type	Method and Description
ValueSelection<V,T>	getValueSelection() Returns value selection criterion
VariableSelection<V,T>	getVariableSelection() Returns variable selection criterion
void	init(Solver<V,T> solver) Initialization -- methods VariableSelection.init(Solver) and ValueSelection.init(Solver) are called.
Neighbour<V,T>	selectNeighbour(Solution<V,T> solution) Select neighbour.
T	selectValue(Solution<V,T> solution, V variable) Use the provided value selection criterion to select a value to the selected variable
V	selectVariable(Solution<V,T> solution) Use the provided variable selection criterion to select a variable
void	setValueSelection(ValueSelection<V,T> valueSelection) Sets value selection criterion
void	setVariableSelection(VariableSelection<V,T> variableSelection) Sets variable selection criterion

Methods inherited from class java.lang.Object

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

Field Detail

sLogger

protected static org.apache.logging.log4j.Logger sLogger

iSolver

protected Solver<V extends Variable<V,T>,T extends Value<V,T>> iSolver

iStat

protected ConflictStatistics<V extends Variable<V,T>,T extends Value<V,T>> iStat

Constructor Detail

StandardNeighbourSelection

public StandardNeighbourSelection(DataProperties properties)
                           throws Exception

Constructor

Parameters:

properties - configuration

Throws:

Exception - thrown when initialization fails

Method Detail

setValueSelection

public void setValueSelection(ValueSelection<V,T> valueSelection)

Sets value selection criterion

Parameters:

valueSelection - value selection criterion

setVariableSelection

public void setVariableSelection(VariableSelection<V,T> variableSelection)

Sets variable selection criterion

Parameters:

variableSelection - variable selection criterion

getValueSelection

public ValueSelection<V,T> getValueSelection()

Returns value selection criterion

Returns:

value selection criterion

getVariableSelection

public VariableSelection<V,T> getVariableSelection()

Returns variable selection criterion

Returns:

variable selection criterion

init

public void init(Solver<V,T> solver)

Initialization -- methods VariableSelection.init(Solver) and ValueSelection.init(Solver) are called.

Specified by:

init in interface NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

solver - current solver

selectVariable

public V selectVariable(Solution<V,T> solution)

Use the provided variable selection criterion to select a variable

Parameters:

solution - current solution

Returns:

selected variable

selectValue

public T selectValue(Solution<V,T> solution,
                     V variable)

Use the provided value selection criterion to select a value to the selected variable

Parameters:

solution - current solution

variable - selected variable

Returns:

selected value

selectNeighbour

public Neighbour<V,T> selectNeighbour(Solution<V,T> solution)

Select neighbour. A value is selected to the selected variable.

Specified by:

selectNeighbour in interface NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

solution - given solution

Returns:

a neighbour assignment