net.sf.cpsolver.ifs.example.csp
Class CSPModel

java.lang.Object
  net.sf.cpsolver.ifs.model.Model
      net.sf.cpsolver.ifs.example.csp.CSPModel

public class CSPModel
extends Model

Random Binary CSP with uniform distribution.

A random CSP is defined by a four-tuple (n, d, p1, p2), where n denotes the number of variables and d denotes the domain size of each variable, p1 and p2 are two probabilities. They are used to generate randomly the binary constraints among the variables. p1 represents the probability that a constraint exists between two different variables and p2 represents the probability that a pair of values in the domains of two variables connected by a constraint are incompatible.

We use a so called model B of Random CSP (n, d, n1, n2) where n1 = p1*n*(n-1)/2 pairs of variables are randomly and uniformly selected and binary constraints are posted between them. For each constraint, n2 = p1*d^2 randomly and uniformly selected pairs of values are picked as incompatible.

Version:

IFS 1.1 (Iterative Forward Search)
Copyright (C) 2006 Tomáš Müller
muller@unitime.org
Lazenska 391, 76314 Zlin, Czech Republic

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 2.1 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Field Summary

Fields inherited from class net.sf.cpsolver.ifs.model.Model

iAssignedVariables, iPerturbVariables, iUnassignedVariables, sDoubleFormat, sPercentageFormat, sTimeFormat

Constructor Summary

CSPModel(int nrVariables, int nrValues, int nrConstraints, int nrCompatiblePairs, long seed)
Constructor

Method Summary

Methods inherited from class net.sf.cpsolver.ifs.model.Model

addConstraint, addGlobalConstraint, addModelListener, addVariable, afterAssigned, afterUnassigned, assignedVariables, beforeAssigned, beforeUnassigned, bestUnassignedVariables, clearBest, conflictConstraints, conflictValues, constraints, countConstraints, countGlobalConstraints, countVariables, getBestPerturbations, getBestUnassignedVariables, getExtendedInfo, getInfo, getInfo, getInfoProviders, getModelListeners, getPerc, getPercRev, getTotalValue, getTotalValue, globalConstraints, inConflict, init, invalidateVariablesWithInitialValueCache, modelListenerOfType, nrAssignedVariables, nrUnassignedVariables, perturbVariables, perturbVariables, removeConstraint, removeGlobalConstraint, removeModelListener, removeVariable, restoreBest, saveBest, toString, unassignedHardConstraints, unassignedVariables, variables, variablesWithInitialValue

Methods inherited from class java.lang.Object

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

Constructor Detail

CSPModel

public CSPModel(int nrVariables,
                int nrValues,
                int nrConstraints,
                int nrCompatiblePairs,
                long seed)

Constructor

Parameters:

nrVariables - number of variables in the problem

nrValues - number of values of each variable

nrConstraints - number of constraints in the problem

nrCompatiblePairs - number of compatible pairs of values for every constraint

seed - seed for random number generator (use System.currentTimeMillis() if not bother)