Package org.graphstream.algorithm.measure

Class ConnectivityMeasure

java.lang.Object
org.graphstream.algorithm.measure.ConnectivityMeasure
public class ConnectivityMeasure
extends Object
Get the vertex-connectivity of a graph. A graph is said to be k-vertex-connected (or k-connected) if the graph remains connected when you delete fewer than k vertices from the graph (from Wikipedia).

  • Nested Class Summary

    Nested Classes 
    Modifier and Type Class Description
    static class  ConnectivityMeasure.EdgeConnectivityMeasure  
    static class  ConnectivityMeasure.VertexConnectivityMeasure  

  • Constructor Summary

    Constructors 
    Constructor Description
    ConnectivityMeasure()  

  • Method Summary

    Modifier and Type Method Description
    static int getEdgeConnectivity​(org.graphstream.graph.Graph g)
    Get the edge-connectivity k of a graph such that there is a k-tuple of edges whose removal disconnects the graph.
    static org.graphstream.graph.Edge[] getKDisconnectingEdgeTuple​(org.graphstream.graph.Graph g, int k)
    Get a k-tuple of edges whose removal causes the disconnection of the graph.
    static org.graphstream.graph.Node[] getKDisconnectingNodeTuple​(org.graphstream.graph.Graph g, int k)
    Get a k-tuple of nodes whose removal causes the disconnection of the graph.
    static int getVertexConnectivity​(org.graphstream.graph.Graph g)
    Get the vertex-connectivity k of a graph such that there is a k-tuple of nodes whose removal disconnects the graph.
    static boolean isKEdgeConnected​(org.graphstream.graph.Graph g, int k)
    Check if a graph is k-edge-connected, ie. there is no (k-1)-edge-tuple such that the removal of these edges leads to disconnect the graph.
    static boolean isKVertexConnected​(org.graphstream.graph.Graph g, int k)
    Check if a graph is k-vertex-connected, ie. there is no (k-1)-node-tuple such that the removal of these nodes leads to disconnect the graph.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

  • Method Details

    • getVertexConnectivity

      public static int getVertexConnectivity​(org.graphstream.graph.Graph g)
      Get the vertex-connectivity k of a graph such that there is a k-tuple of nodes whose removal disconnects the graph.
      Parameters:
      g - the graph
      Returns:
      vertex connectivity

    • getEdgeConnectivity

      public static int getEdgeConnectivity​(org.graphstream.graph.Graph g)
      Get the edge-connectivity k of a graph such that there is a k-tuple of edges whose removal disconnects the graph. This uses the Ford-Fulkerson algorithm to compute maximum flows in the graph. A simple algorithm would, for every pair (u,v), determine the maximum flow from u to v with the capacity of all edges in G set to 1 for both directions. A graph is k-edge-connected if and only if the maximum flow from u to v is at least k for any pair (u,v), so k is the least u-v-flow among all (u,v). Source Wikipedia.
      Parameters:
      g - the graph
      Returns:
      edge connectivity

    • isKVertexConnected

      public static boolean isKVertexConnected​(org.graphstream.graph.Graph g, int k)
      Check if a graph is k-vertex-connected, ie. there is no (k-1)-node-tuple such that the removal of these nodes leads to disconnect the graph.
      Parameters:
      g - the graph
      k - connectivity being checked
      Returns:
      true if g is k-vertex-connected

    • isKEdgeConnected

      public static boolean isKEdgeConnected​(org.graphstream.graph.Graph g, int k)
      Check if a graph is k-edge-connected, ie. there is no (k-1)-edge-tuple such that the removal of these edges leads to disconnect the graph.
      Parameters:
      g - the graph
      k - connectivity being checked
      Returns:
      true if g is k-edge-connected

    • getKDisconnectingNodeTuple

      public static org.graphstream.graph.Node[] getKDisconnectingNodeTuple​(org.graphstream.graph.Graph g, int k)
      Get a k-tuple of nodes whose removal causes the disconnection of the graph.
      Parameters:
      g - the graph
      k - max size of the required tuple
      Returns:
      a k-tuple of nodes or null if graph is (k+1)-vertex-connected

    • getKDisconnectingEdgeTuple

      public static org.graphstream.graph.Edge[] getKDisconnectingEdgeTuple​(org.graphstream.graph.Graph g, int k)
      Get a k-tuple of edges whose removal causes the disconnection of the graph.
      Parameters:
      g - the graph
      k - max size of the required tuple
      Returns:
      a k-tuple of edges or null if graph is (k+1)-edge-connected