net.walend.measured
Class AbstractShortestGEDistances

java.lang.Object
  |
  +--net.walend.measured.AbstractShortestGEDistances

All Implemented Interfaces:

HasState, java.io.Serializable, ShortestGEDistances

Direct Known Subclasses:

DijkstraShortestGEDistances, FloydWarshallShortestGEDistances

public abstract class AbstractShortestGEDistances

extends java.lang.Object

implements ShortestGEDistances, java.io.Serializable

AbstractShortestGEDistances contains a 2D array of distances between nodes in a directed graph. This class holds a lot of common workhorse methods used by other classes.

Author:

David Walend dfw1@cornell.edu

See Also:

Serialized Form

Field Summary

private IndexedGEDigraph	base
private int[][]	distances
private GEPathMeter	pathMeter

Constructor Summary

protected

AbstractShortestGEDistances(IndexedGEDigraph ceDigraph, GEPathMeter pathMeter)

Method Summary

protected void	bfTest()
IndexedGEDigraph	getBase()
int	getLength(int from, int to)
int	getLength(java.lang.Object fromNode, java.lang.Object toNode)
GEPathMeter	getPathMeter() Return the path meter used to evaluate these shortest paths.
java.lang.Class	getPrincipleInterface() Returns the class's principle interface for state comparisons.
protected void	initializeDistances()
abstract void	recalculate() Rediscover the shortest paths.
protected void	relax(int fromIndex, int throughIndex, int toIndex)
protected int	safeLength(int from, int to)
boolean	sameStateAs(HasState victim) If two HasStates have the same internal state, return true.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

distances

private int[][] distances

pathMeter

private GEPathMeter pathMeter

base

private IndexedGEDigraph base

Constructor Detail

AbstractShortestGEDistances

protected AbstractShortestGEDistances(IndexedGEDigraph ceDigraph,
                                      GEPathMeter pathMeter)
                               throws GENegativeWeightCycleException

Method Detail

bfTest

protected void bfTest()
               throws GENegativeWeightCycleException

GENegativeWeightCycleException

getBase

public IndexedGEDigraph getBase()

Specified by:

getBase in interface ShortestGEDistances

initializeDistances

protected void initializeDistances()

relax

protected void relax(int fromIndex,
                     int throughIndex,
                     int toIndex)

recalculate

public abstract void recalculate()
                          throws GENegativeWeightCycleException

Rediscover the shortest paths.

Specified by:

recalculate in interface ShortestGEDistances

GENegativeWeightCycleException

getPathMeter

public GEPathMeter getPathMeter()

Return the path meter used to evaluate these shortest paths.

Specified by:

getPathMeter in interface ShortestGEDistances

getLength

public int getLength(int from,
                     int to)

Specified by:

getLength in interface ShortestGEDistances

safeLength

protected final int safeLength(int from,
                               int to)

getLength

public int getLength(java.lang.Object fromNode,
                     java.lang.Object toNode)
              throws NodeMissingException

Specified by:

getLength in interface ShortestGEDistances

NodeMissingException

getPrincipleInterface

public java.lang.Class getPrincipleInterface()

Description copied from interface: HasState

Returns the class's principle interface for state comparisons. If two objects have different principle interfaces, they never have the same state.

Specified by:

getPrincipleInterface in interface HasState

sameStateAs

public boolean sameStateAs(HasState victim)

Description copied from interface: HasState

If two HasStates have the same internal state, return true.

For objects with subobjects, Generally this method should only return true if the internal objects are equal. Implement a contentsHaveSameState() method to determine if the contents have the same state.

Specified by:

sameStateAs in interface HasState

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object