com.sparsity.dex.algorithms
Class WeakConnectivity

java.lang.Object
  extended by com.sparsity.dex.algorithms.Connectivity
      extended by com.sparsity.dex.algorithms.WeakConnectivity
All Implemented Interfaces:
java.io.Closeable
Direct Known Subclasses:
WeakConnectivityDFS

public class WeakConnectivity
extends Connectivity

WeakConnectivity class.

Any class implementing this abstract class can be used to solve the problem of finding weakly connected components in an undirected graph or in a directed graph which will be considered as an undirected one.

It consists in finding components where every pair (u,v) of nodes contained in it has a path from u to v and from v to u.

It is possible to set some restrictions after constructing a new instance of this class and before running it in order to limit the results.

After the execution, we can retrieve the results stored in an instance of the ConnectedComponents class using the getConnectedComponents method.

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()
          Allows connectivity through all edge types of the graph.
 void addAllNodeTypes()
          Allows connectivity through all node types of the graph.
 void addEdgeType(int t)
          Allows connectivity through edges of the given type.
 void addNodeType(int t)
          Allows connectivity through 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.
 ConnectedComponents getConnectedComponents()
          Returns the results generated by the execution of the algorithm.
 void run()
          Runs the algorithm in order to find the connected components.
 void setMaterializedAttribute(java.lang.String attributeName)
          Creates a new common attribute type for all node types in the graph in order to store, persistently, the results related to the connected components found while executing this algorithm.
 
Methods inherited from class com.sparsity.dex.algorithms.Connectivity
close, isClosed
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

addAllNodeTypes

public void addAllNodeTypes()
Allows connectivity through all node types of the graph.

Overrides:
addAllNodeTypes in class Connectivity

addAllEdgeTypes

public void addAllEdgeTypes()
Allows connectivity through all edge types of the graph.

In a weak connectivity the edges can be used in Any direction. d[in] Edge direction.


run

public void run()
Runs the algorithm in order to find the connected components.

This method can be called only once.

Overrides:
run in class Connectivity

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

addEdgeType

public void addEdgeType(int t)
Allows connectivity through edges of the given type.

In a weak connectivity the edges can be used in Any direction. d[in] Edge direction.

Parameters:
t - [in] Edge type.

setMaterializedAttribute

public void setMaterializedAttribute(java.lang.String attributeName)
Creates a new common attribute type for all node types in the graph in order to store, persistently, the results related to the connected components found while executing this algorithm.

Whenever the user wants to retrieve the results, even when the graph has been closed and opened again, it is only necessary to create a new instance of the class ConnectedComponents indicating the graph and the name of the common attribute type which stores the results. This instance will have all the information related to the connected components found in the moment of the execution of the algorithm that stored this data.

It is possible to run the algorithm without specifying this parameter in order to avoid materializing the results of the execution.

Overrides:
setMaterializedAttribute in class Connectivity
Parameters:
attributeName - [in] The name of the common attribute type for all node types in the graph which will store persistently the results generated by the execution of the algorithm.

addNodeType

public void addNodeType(int t)
Allows connectivity through nodes of the given type.

Overrides:
addNodeType in class Connectivity
Parameters:
t - null

getConnectedComponents

public ConnectedComponents getConnectedComponents()
Returns the results generated by the execution of the algorithm.

These results contain information related to the connected components found as the number of different components, the set of nodes contained in each component or many other data.

Overrides:
getConnectedComponents in class Connectivity
Returns:
Returns an instance of the class ConnectedComponents which contain information related to the connected components found.

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