Package org.tweetyproject.math.opt.solver

Class IteratedLocalSearchOnConstrProb

java.lang.Object

org.tweetyproject.math.opt.solver.Solver

org.tweetyproject.math.opt.solver.IteratedLocalSearchOnConstrProb

public class IteratedLocalSearchOnConstrProb
extends Solver

implements the Iterates local search algorithm for optimization problems

Author:

Sebastian Franke

Constructor Summary

Constructors

Constructor	Description
IteratedLocalSearchOnConstrProb(double perturbationStrength, int maxnumberOfRestarts, int maxIterations)	Constructor

Method Summary

Modifier and Type	Method	Description
Map<Variable,Term>	bestNeighbor(Map<Variable,Term> currSol, int minIterations, int maxIterations, double threshold, Term t)	Return the best solution that was found and is a mutant of currSol
double	evaluate(Map<Variable,Term> sol, Term minT)	Return the evaluation
Map<Variable,Term>	pertubate(Map<Variable,Term> currSol)	changes the solution drastically to escape a local minimum
Map<Variable,Term>	solve(GeneralConstraintSatisfactionProblem problem)	Computes a solution to the given constraint satisfaction or optimization problem, i.e.

Methods inherited from class org.tweetyproject.math.opt.solver.Solver

getDefaultGeneralSolver, getDefaultIntegerLinearSolver, getDefaultLinearSolver, hasDefaultGeneralSolver, hasDefaultIntegerLinearSolver, hasDefaultLinearSolver, isInstalled, setDefaultGeneralSolver, setDefaultIntegerLinearSolver, setDefaultLinearSolver

Methods inherited from class java.lang.Object

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

Constructor Details

IteratedLocalSearchOnConstrProb

public IteratedLocalSearchOnConstrProb(double perturbationStrength,
 int maxnumberOfRestarts,
 int maxIterations)

Constructor

Parameters:

perturbationStrength - perturbationStrength

maxnumberOfRestarts - maxnumberOfRestarts

maxIterations - maxIterations

Method Details

bestNeighbor

public Map<Variable,Term> bestNeighbor(Map<Variable,Term> currSol,
 int minIterations,
 int maxIterations,
 double threshold,
 Term t)

Return the best solution that was found and is a mutant of currSol

Parameters:

currSol - : the solution that every newly created solution uses as a initial solution in createNewSol

minIterations - : the minimum amount of solutions to be created

maxIterations - : the maximum amount of solutions to be created

threshold - : if a solution with the quality of threshold is reached we do maximum 10 more tries

t - : some term

Returns:

the best solution that was found and is a mutant of currSol

pertubate

public Map<Variable,Term> pertubate(Map<Variable,Term> currSol)

changes the solution drastically to escape a local minimum

Parameters:

currSol - the solution to be pertubated

Returns:

a new mapping

evaluate

public double evaluate(Map<Variable,Term> sol,
 Term minT)

Return the evaluation

Parameters:

sol - sol

minT - minT

Returns:

the evaluation

solve

public Map<Variable,Term> solve(GeneralConstraintSatisfactionProblem problem)

Description copied from class: Solver

Computes a solution to the given constraint satisfaction or optimization problem, i.e. a mapping from variables of the problem to terms.

Specified by:

solve in class Solver

Parameters:

problem - the actual problem

Returns:

a mapping from variables of the problem to terms.