org.cpsolver.ifs.heuristics

Interface ValueSelection<V extends Variable<V,T>,T extends Value<V,T>>

Type Parameters:

V - Variable

T - Value

All Known Implementing Classes:

DbtValueSelection, EnrollmentSelection, ExamTabuSearch, GeneralValueSelection, PlacementSelection

public interface ValueSelection<V extends Variable<V,T>,T extends Value<V,T>>

Value selection criterion.

After a variable is selected, we need to find a value to be assigned to the variable. This problem is usually called "value selection" in constraint programming. Typically, the most useful advice is to select the best-fit value. So, we are looking for a value which is the most preferred for the variable and which causes the least trouble as well. This means that we need to find a value with the minimal potential for future conflicts with other variables. For example, a value which violates the smallest number of soft constraints can be selected among those with the smallest number of hard conflicts.

The task of this criterion is to select a value of the given variable which will be assigned to this variable.

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

Method Summary

Modifier and Type	Method and Description
void	init(Solver<V,T> solver) Initialization
T	selectValue(Solution<V,T> solution, V selectedVariable) Value selection

Method Detail

init

void init(Solver<V,T> solver)

Initialization

Parameters:

solver - current solver

selectValue

T selectValue(Solution<V,T> solution,
              V selectedVariable)

Value selection

Parameters:

solution - current solution

selectedVariable - selected variable

Returns:

selected value (of the given variable)