org.cpsolver.studentsct.heuristics

Class StudentSctNeighbourSelection

java.lang.Object

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

org.cpsolver.ifs.heuristics.RoundRobinNeighbourSelection<Request,Enrollment>

org.cpsolver.studentsct.heuristics.StudentSctNeighbourSelection

All Implemented Interfaces:

NeighbourSelection<Request,Enrollment>, SolverListener<Request,Enrollment>

Direct Known Subclasses:

TwoPhaseStudentSctNeighbourSelection

public class StudentSctNeighbourSelection
extends RoundRobinNeighbourSelection<Request,Enrollment>
implements SolverListener<Request,Enrollment>

(Batch) student sectioning neighbour selection. It is based on RoundRobinNeighbourSelection, the following steps are involved:

• Phase 1: section all students using incremental branch & bound (no unassignments) (BranchBoundSelection is used)
• Phase 2: pick a student (one by one) with an incomplete schedule, try to find an improvement (SwapStudentSelection is used)
• Phase 3: use standard value selection for some time ( StandardSelection is used)
• Phase 4: use backtrack neighbour selection (BacktrackSelection is used)
• Phase 5: pick a student (one by one) with an incomplete schedule, try to find an improvement, identify problematic students ( SwapStudentSelection is used)
• Phase 6: random unassignment of some problematic students ( RndUnProblStudSelection is used)
• Phase 7: resection incomplete students ( ResectionIncompleteStudentsSelection is used)
• Phase 8: resection of students that were unassigned in step 6 ( ResectionUnassignedStudentsSelection is used)
• Phase 9: pick a student (one by one) with an incomplete schedule, try to find an improvement (SwapStudentSelection is used)
• Phase 10: use standard value selection for some time ( StandardSelection with RouletteWheelRequestSelection is used)
• Phase 11: pick a student (one by one) with an incomplete schedule, try to find an improvement (SwapStudentSelection is used)
• Phase 12: use backtrack neighbour selection (BacktrackSelection is used)
• Phase 13: random unassignment of some students ( RandomUnassignmentSelection is used)

Version:

StudentSct 1.3 (Student Sectioning)
Copyright (C) 2007 - 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

Field Summary

Fields inherited from class org.cpsolver.ifs.heuristics.RoundRobinNeighbourSelection

iSolver, sLogger

Fields inherited from class org.cpsolver.ifs.heuristics.StandardNeighbourSelection

iStat

Constructor Summary

Constructors

Constructor and Description
StudentSctNeighbourSelection(DataProperties properties)

Method Summary

Modifier and Type	Method and Description
void	changeSelection(int selectionIndex) Change selection
void	init(Solver<Request,Enrollment> solver) Initialization
void	neighbourFailed(Assignment<Request,Enrollment> assignment, long iteration, Neighbour<Request,Enrollment> neighbour) Called when ParallelSolver failed to assign the given neighbour
boolean	neighbourSelected(Assignment<Request,Enrollment> assignment, long iteration, Neighbour<Request,Enrollment> neighbour) A neighbour was selected
void	setup(Solver<Request,Enrollment> solver)
boolean	valueSelected(Assignment<Request,Enrollment> assignment, long iteration, Request variable, Enrollment value) A value was selected
boolean	variableSelected(Assignment<Request,Enrollment> assignment, long iteration, Request variable) A variable was selected

Methods inherited from class org.cpsolver.ifs.heuristics.RoundRobinNeighbourSelection

getSelection, getSelectionIndex, registerSelection, selectNeighbour

Methods inherited from class org.cpsolver.ifs.heuristics.StandardNeighbourSelection

getValueSelection, getVariableSelection, selectValue, selectVariable, setValueSelection, setVariableSelection

Methods inherited from class java.lang.Object

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

Constructor Detail

StudentSctNeighbourSelection

public StudentSctNeighbourSelection(DataProperties properties)
                             throws Exception

Throws:

Exception

Method Detail

init

public void init(Solver<Request,Enrollment> solver)

Description copied from class: RoundRobinNeighbourSelection

Initialization

Specified by:

init in interface NeighbourSelection<Request,Enrollment>

Overrides:

init in class RoundRobinNeighbourSelection<Request,Enrollment>

Parameters:

solver - current solver

setup

public void setup(Solver<Request,Enrollment> solver)

changeSelection

public void changeSelection(int selectionIndex)

Description copied from class: RoundRobinNeighbourSelection

Change selection

Overrides:

changeSelection in class RoundRobinNeighbourSelection<Request,Enrollment>

Parameters:

selectionIndex - current selection index

variableSelected

public boolean variableSelected(Assignment<Request,Enrollment> assignment,
                                long iteration,
                                Request variable)

Description copied from interface: SolverListener

A variable was selected

Specified by:

variableSelected in interface SolverListener<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

variable - selected variable

Returns:

if false is returned the variable will be discarded (search continues with the next variable selection)

valueSelected

public boolean valueSelected(Assignment<Request,Enrollment> assignment,
                             long iteration,
                             Request variable,
                             Enrollment value)

Description copied from interface: SolverListener

A value was selected

Specified by:

valueSelected in interface SolverListener<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

variable - selected variable

value - selected variable

Returns:

if false is returned the selected value is not assigned

neighbourSelected

public boolean neighbourSelected(Assignment<Request,Enrollment> assignment,
                                 long iteration,
                                 Neighbour<Request,Enrollment> neighbour)

Description copied from interface: SolverListener

A neighbour was selected

Specified by:

neighbourSelected in interface SolverListener<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

neighbour - neighbour

Returns:

if false is returned the selected neighbour is not assigned

neighbourFailed

public void neighbourFailed(Assignment<Request,Enrollment> assignment,
                            long iteration,
                            Neighbour<Request,Enrollment> neighbour)

Description copied from interface: SolverListener

Called when ParallelSolver failed to assign the given neighbour

Specified by:

neighbourFailed in interface SolverListener<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

neighbour - neighbour