DexNet  4.8.2
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com.sparsity.dex.algorithms.StrongConnectivityGabow Class Reference

This class can be used to solve the problem of finding strongly connected components in a directed graph. More...

Inheritance diagram for com.sparsity.dex.algorithms.StrongConnectivityGabow:
Inheritance graph
Collaboration diagram for com.sparsity.dex.algorithms.StrongConnectivityGabow:
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Public Member Functions

 StrongConnectivityGabow (com.sparsity.dex.gdb.Session s)
 Creates a new instance of StrongConnectivityGabow. More...
 
void AddAllNodeTypes ()
 Allows connectivity through all node types of the graph.
 
void AddAllEdgeTypes (com.sparsity.dex.gdb.EdgesDirection d)
 Allows connectivity through all edge types of the graph. More...
 
void ExcludeNodes (com.sparsity.dex.gdb.Objects nodes)
 Set which nodes can't be used. More...
 
void Run ()
 Executes the algorithm.
 
void AddEdgeType (int t, com.sparsity.dex.gdb.EdgesDirection d)
 Allows connectivity through edges of the given type. More...
 
void SetMaterializedAttribute (System.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. More...
 
void AddNodeType (int t)
 Allows connectivity through nodes of the given type. More...
 
com.sparsity.dex.algorithms.ConnectedComponents GetConnectedComponents ()
 Returns the results generated by the execution of the algorithm. More...
 
void ExcludeEdges (com.sparsity.dex.gdb.Objects edges)
 Set which edges can't be used. More...
 
boolean IsClosed ()
 Gets if Connectivity instance has been closed or not. More...
 
void Close ()
 Closes the Connectivity instance. More...
 

Detailed Description

This class can be used to solve the problem of finding strongly connected components in a directed graph.

It consists in finding components where every pair (u,v) of nodes contained in it has a path from u to v using the specified direction for each edge type. This implementation is based on the Gabow algorithm.

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

Constructor & Destructor Documentation

com.sparsity.dex.algorithms.StrongConnectivityGabow.StrongConnectivityGabow ( com.sparsity.dex.gdb.Session  s)

Creates a new instance of StrongConnectivityGabow.

After creating this instance is required to indicate the set of edge types and the set of node types which will be navigated through while traversing the graph in order to find the strong connected components.

Parameters
s[in] Session to get the graph from and calculate the connectivity

Member Function Documentation

void com.sparsity.dex.algorithms.StrongConnectivityGabow.AddAllEdgeTypes ( com.sparsity.dex.gdb.EdgesDirection  d)

Allows connectivity through all edge types of the graph.

Parameters
d[in] Edge direction.
void com.sparsity.dex.algorithms.StrongConnectivityGabow.AddEdgeType ( int  t,
com.sparsity.dex.gdb.EdgesDirection  d 
)

Allows connectivity through edges of the given type.

Parameters
t[in] Edge type.
d[in] Edge direction.
void com.sparsity.dex.algorithms.StrongConnectivityGabow.AddNodeType ( int  t)

Allows connectivity through nodes of the given type.

Parameters
tnull
void com.sparsity.dex.algorithms.Connectivity.Close ( )
inherited

Closes the Connectivity instance.

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

void com.sparsity.dex.algorithms.StrongConnectivityGabow.ExcludeEdges ( com.sparsity.dex.gdb.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.

Parameters
edges[in] A set of edge identifiers that must be kept intact until the destruction of the class.
void com.sparsity.dex.algorithms.StrongConnectivityGabow.ExcludeNodes ( com.sparsity.dex.gdb.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.

Parameters
nodes[in] A set of node identifiers that must be kept intact until the destruction of the class.
com.sparsity.dex.algorithms.ConnectedComponents com.sparsity.dex.algorithms.StrongConnectivityGabow.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.

Returns
Returns an instance of the class ConnectedComponents which contain information related to the connected components found.
boolean com.sparsity.dex.algorithms.Connectivity.IsClosed ( )
inherited

Gets if Connectivity instance has been closed or not.

See Also
Close()
Returns
TRUE if the Connectivity instance has been closed, FALSE otherwise.
void com.sparsity.dex.algorithms.StrongConnectivityGabow.SetMaterializedAttribute ( System.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.

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.