org.cpsolver.ifs.algorithms

Class SimulatedAnnealing.SimulatedAnnealingContext

java.lang.Object

org.cpsolver.ifs.algorithms.NeighbourSearch.NeighbourSearchContext

org.cpsolver.ifs.algorithms.SimulatedAnnealing.SimulatedAnnealingContext

All Implemented Interfaces:

AssignmentContext, SolutionListener<V,T>

Enclosing class:

SimulatedAnnealing<V extends Variable<V,T>,T extends Value<V,T>>

public class SimulatedAnnealing.SimulatedAnnealingContext
extends NeighbourSearch.NeighbourSearchContext

Field Summary

Fields inherited from class org.cpsolver.ifs.algorithms.NeighbourSearch.NeighbourSearchContext

iIter, iT0

Constructor Summary

Constructors

Constructor and Description
SimulatedAnnealingContext()

Method Summary

Modifier and Type	Method and Description
protected boolean	accept(Assignment<V,T> assignment, Model<V,T> model, Neighbour<V,T> neighbour, double value, boolean lazy) True if the given neighbour is to be be accepted
protected void	activate(Solution<V,T> solution) Setup the temperature
void	bestSaved(Solution<V,T> solution) Memorize the iteration when the last best solution was found.
protected void	cool(Solution<V,T> solution) Cool temperature
protected double	getCoolingRate(int idx)
protected void	incIteration(Solution<V,T> solution) Increment iteration counter, cool/reheat/restoreBest if necessary
protected double	prob(double value) Neighbour acceptance probability
protected double	prob(double value, double temp) Neighbour acceptance probability
protected void	reheat(Solution<V,T> solution) Reheat temperature
protected void	restoreBest(Solution<V,T> solution) restore best ever found solution
protected void	train(Solution<V,T> solution) Set initial temperature based on the training period

Methods inherited from class org.cpsolver.ifs.algorithms.NeighbourSearch.NeighbourSearchContext

bestCleared, bestRestored, canContinue, deactivate, getInfo, getInfo, getTimeMillis, solutionUpdated

Methods inherited from class java.lang.Object

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

Constructor Detail

SimulatedAnnealingContext

public SimulatedAnnealingContext()

Method Detail

activate

protected void activate(Solution<V,T> solution)

Setup the temperature

Overrides:

activate in class NeighbourSearch.NeighbourSearchContext

Parameters:

solution - current solution

getCoolingRate

protected double getCoolingRate(int idx)

train

protected void train(Solution<V,T> solution)

Set initial temperature based on the training period

Parameters:

solution - current solution

cool

protected void cool(Solution<V,T> solution)

Cool temperature

Parameters:

solution - current solution

reheat

protected void reheat(Solution<V,T> solution)

Reheat temperature

Parameters:

solution - current solution

restoreBest

protected void restoreBest(Solution<V,T> solution)

restore best ever found solution

Parameters:

solution - current solution

prob

protected double prob(double value)

Neighbour acceptance probability

Parameters:

value - absolute or relative value of the proposed change (neighbour)

Returns:

probability of acceptance of a change (neighbour)

prob

protected double prob(double value,
                      double temp)

Neighbour acceptance probability

Parameters:

value - absolute or relative value of the proposed change (neighbour)

temp - current temperature

Returns:

probability of acceptance of a change (neighbour)

accept

protected boolean accept(Assignment<V,T> assignment,
                         Model<V,T> model,
                         Neighbour<V,T> neighbour,
                         double value,
                         boolean lazy)

True if the given neighbour is to be be accepted

Specified by:

accept in class NeighbourSearch.NeighbourSearchContext

Parameters:

assignment - current assignment

neighbour - proposed move

model - problem model

value - value of the generated move (i.e., its impact on the solution value)

lazy - true if lazy move

Returns:

true if generated random number is below the generated probability

incIteration

protected void incIteration(Solution<V,T> solution)

Increment iteration counter, cool/reheat/restoreBest if necessary

Overrides:

incIteration in class NeighbourSearch.NeighbourSearchContext

Parameters:

solution - current solution

bestSaved

public void bestSaved(Solution<V,T> solution)

Memorize the iteration when the last best solution was found.

Specified by:

bestSaved in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>

Overrides:

bestSaved in class NeighbourSearch.NeighbourSearchContext

Parameters:

solution - source solution