com.sparsity.sparksee.algorithms

Class KOpt

java.lang.Object

com.sparsity.sparksee.algorithms.KOpt

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class KOpt
extends java.lang.Object
implements java.io.Closeable

KOpt class.

Implements the 2-Opt and 3-Opt algorithms

Author:

Sparsity Technologies http://www.sparsity-technologies.com

Constructor Summary

Constructors

Constructor and Description
KOpt(Session session) Creates a new instance.
KOpt(Session session, OIDList tour) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
void	addAllEdgeTypes(EdgesDirection dir) Allows for traversing all edge types of the graph.
void	addAllNodeTypes() Allows for traversing all node types of the graph.
void	addEdgeType(int type, EdgesDirection dir) Allows for traversing edges of the given type.
void	addNodeType(int type) Allows for traversing nodes of the given type.
void	close() Closes the KOpt instance.
double	getCurrentCost() Returns tour cost.
OIDList	getCurrentTour() Returns tour as a list of nodes.
boolean	isClosed() Gets if KOpt instance has been closed or not.
void	runThreeOpt() Runs 3-Opt local search.
void	runTwoOpt() Runs 2-Opt local search.
void	setCurrentTour(OIDList tour) Sets current tour as a list of nodes.
void	setEdgeWeightAttributeType(int attr) Sets the attribute to use as edge weight.
void	setMaxIterations(long maxIterations) Sets maximum number of iterations.
void	setTimeLimit(long maxTime) Limits execution time.

Methods inherited from class java.lang.Object

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

Constructor Detail

KOpt

public KOpt(Session session,
            OIDList tour)

Creates a new instance.

Parameters:

session - [in] Session to get the graph from and perform algorithm.

tour - [in] Initial tour that needs to be improved.

KOpt

public KOpt(Session session)

Creates a new instance.

Parameters:

session - [in] Session to get the graph from and perform algorithm.

Method Detail

setCurrentTour

public void setCurrentTour(OIDList tour)

Sets current tour as a list of nodes.

Parameters:

tour - [in] Initial tour that needs to be improved.

getCurrentCost

public double getCurrentCost()

Returns tour cost.

addAllEdgeTypes

public void addAllEdgeTypes(EdgesDirection dir)

Allows for traversing all edge types of the graph.

Parameters:

dir - [in] Edge direction.

getCurrentTour

public OIDList getCurrentTour()

Returns tour as a list of nodes.

setEdgeWeightAttributeType

public void setEdgeWeightAttributeType(int attr)
                                throws java.lang.RuntimeException

Sets the attribute to use as edge weight.

If the multiple edge are set for traversal, this attribute must be of type GLOBAL_TYPE or EDGES_TYPE. Additionally, the attribute must be of type Double.

sparksee::gdb::Error

Parameters:

attr - [in] The attribute type to use as a weight. Default: InvalidAttribute

Throws:

java.lang.RuntimeException - null

runTwoOpt

public void runTwoOpt()

Runs 2-Opt local search.

addEdgeType

public void addEdgeType(int type,
                        EdgesDirection dir)
                 throws java.lang.RuntimeException

Allows for traversing edges of the given type.

If the edge type was already added, the existing direction is overwritten

Parameters:

type - [in] Edge type.

dir - [in] Edge direction.

Throws:

java.lang.RuntimeException - null

runThreeOpt

public void runThreeOpt()

Runs 3-Opt local search.

isClosed

public boolean isClosed()

Gets if KOpt instance has been closed or not.

Returns:

TRUE if the KOpt instance has been closed, FALSE otherwise.

See Also:

close()

setMaxIterations

public void setMaxIterations(long maxIterations)

Sets maximum number of iterations.

By default the algorithm will run until no improvement can be made in the current tour.

Parameters:

maxIterations - [in] Maximum number of iterations

setTimeLimit

public void setTimeLimit(long maxTime)

Limits execution time.

Parameters:

maxTime - [in] Time limit in miliseconds

addNodeType

public void addNodeType(int type)
                 throws java.lang.RuntimeException

Allows for traversing nodes of the given type.

sparksee::gdb::Error

Parameters:

type - [in] Node type.

Throws:

java.lang.RuntimeException - null

close

public void close()

Closes the KOpt instance.

It must be called to ensure the integrity of all data.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

addAllNodeTypes

public void addAllNodeTypes()

Allows for traversing all node types of the graph.