com.sparsity.dex.algorithms
Class SinglePairShortestPath

java.lang.Object
  extended by com.sparsity.dex.algorithms.ShortestPath
      extended by com.sparsity.dex.algorithms.SinglePairShortestPath
All Implemented Interfaces:
java.io.Closeable
Direct Known Subclasses:
SinglePairShortestPathBFS, SinglePairShortestPathDijkstra

public class SinglePairShortestPath
extends ShortestPath

SinglePairShortestPath class.

Classes implementing this abstract class solve the shortest path problem in a graph from a given source node and to a given destination node.

Check out the 'Algorithms' section in the DEX User Manual for more details on this.

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

Method Summary
 void addAllEdgeTypes(EdgesDirection d)
          Allows for traversing all edge types of the graph.
 void addAllNodeTypes()
          Allows for traversing all node types of the graph.
 void addEdgeType(int t, EdgesDirection d)
          Allows for traversing edges of the given type.
 void addNodeType(int t)
          Allows for traversing nodes of the given type.
 void excludeEdges(Objects edges)
          Set which edges can't be used.
 void excludeNodes(Objects nodes)
          Set which nodes can't be used.
 boolean exists()
          Returns TRUE If a path exists or FALSE otherwise.
 double getCost()
          Gets the cost of the shortest path.
 OIDList getPathAsEdges()
          Gets the shortest path between the source node and the destination node as an ordered set of edges.
 OIDList getPathAsNodes()
          Gets the shortest path between the source node and the destination node as an ordered set of nodes.
 void run()
          Runs the algorithm.
 void setMaximumHops(int maxhops)
          Sets the maximum hops restriction.
 
Methods inherited from class com.sparsity.dex.algorithms.ShortestPath
close, isClosed
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

exists

public boolean exists()
Returns TRUE If a path exists or FALSE otherwise.


run

public void run()
Runs the algorithm.

This method can only be called once.

Overrides:
run in class ShortestPath

addEdgeType

public void addEdgeType(int t,
                        EdgesDirection d)
Allows for traversing edges of the given type.

Overrides:
addEdgeType in class ShortestPath
Parameters:
t - [in] Edge type.
d - [in] Edge direction.

addNodeType

public void addNodeType(int t)
Allows for traversing nodes of the given type.

Overrides:
addNodeType in class ShortestPath
Parameters:
t - null

getPathAsEdges

public OIDList getPathAsEdges()
Gets the shortest path between the source node and the destination node as an ordered set of edges.

Returns:
Ordered set of edge identifiers.

excludeEdges

public void excludeEdges(Objects edges)
Set which edges can't be used.

This will replace any previously specified set of excluded edges. Should only be used to exclude the usage of specific edges from allowed edge types because it's less efficient than not allowing an edge type.

Overrides:
excludeEdges in class ShortestPath
Parameters:
edges - [in] A set of edge identifiers that must be kept intact until the destruction of the class.

addAllNodeTypes

public void addAllNodeTypes()
Allows for traversing all node types of the graph.

Overrides:
addAllNodeTypes in class ShortestPath

addAllEdgeTypes

public void addAllEdgeTypes(EdgesDirection d)
Allows for traversing all edge types of the graph.

Overrides:
addAllEdgeTypes in class ShortestPath
Parameters:
d - [in] Edge direction.

excludeNodes

public void excludeNodes(Objects nodes)
Set which nodes can't be used.

This will replace any previously specified set of excluded nodes. Should only be used to exclude the usage of specific nodes from allowed node types because it's less efficient than not allowing a node type.

Overrides:
excludeNodes in class ShortestPath
Parameters:
nodes - [in] A set of node identifiers that must be kept intact until the destruction of the class.

getCost

public double getCost()
Gets the cost of the shortest path.

The cost for unweighted algorithms is the number of hops of the shortest path. For weighted algoritms, the cost is the sum of the costs of the edges of the shortest path.

Returns:
The cost of the shortest path.

getPathAsNodes

public OIDList getPathAsNodes()
Gets the shortest path between the source node and the destination node as an ordered set of nodes.

Returns:
Ordered set of node identifiers.

setMaximumHops

public void setMaximumHops(int maxhops)
Sets the maximum hops restriction.

All paths longer than the maximum hops restriction will be ignored. m[in] The maximum hops restriction. It must be positive or zero. Zero, the default value, means unlimited.

Overrides:
setMaximumHops in class ShortestPath
Parameters:
maxhops - null