Package org.graphstream.algorithm.measure

Class SurpriseMeasure

java.lang.Object
org.graphstream.algorithm.measure.SurpriseMeasure
All Implemented Interfaces:
Algorithm
public class SurpriseMeasure
extends Object
implements Algorithm
Surprise measure. Description from Wikipedia : Surprise (denoted S) is a measure of community structure in complex networks. The name Surprise derives from the fact that its maximization finds the most surprising partition into communities of the network, that is, the most unlikely one. S accurately evaluates, in a global manner, the quality of a partition using a cumulative hypergeometric distribution.
Scientific Reference :
Rodrigo Aldecoa, Ignacio Marin, "Deciphering Network Community Structure by Surprise", 2011, PLoS ONE 6(9)

  • Field Details

  • Constructor Details

    • SurpriseMeasure

      public SurpriseMeasure()
      Default constructor.

    • SurpriseMeasure

      public SurpriseMeasure​(String communityAttributeKey)
      Constructor allowing to set the node attribute key containing index of organizations.
      Parameters:
      communityAttributeKey - key attribute of organizations

    • SurpriseMeasure

      public SurpriseMeasure​(String communityAttributeKey, String surpriseAttributeKey)
      Same as SurpriseMeasure(String) but allowing to set the graph attribute that will contain the result of the computation.
      Parameters:
      communityAttributeKey - community attribute key
      surpriseAttributeKey - surprise attribute key

  • Method Details

    • init

      public void init​(org.graphstream.graph.Graph graph)
      Description copied from interface: Algorithm
      Initialization of the algorithm. This method has to be called before the Algorithm.compute() method to initialize or reset the algorithm according to the new given graph.
      Specified by:
      init in interface Algorithm
      Parameters:
      graph - The graph this algorithm is using.

    • compute

      public void compute()
      Description copied from interface: Algorithm
      Run the algorithm. The Algorithm.init(Graph) method has to be called before computing.
      Specified by:
      compute in interface Algorithm
      See Also:
      Algorithm.init(Graph)

    • defaultResult

      public String defaultResult()

    • setCommunityAttributeKey

      public void setCommunityAttributeKey​(String communityAttributeKey)

    • getSurprise

      public double getSurprise()
      Get the last computed surprise value contained in the graph.
      Returns:
      surprise value

    • binomialCoefficient

      public static double binomialCoefficient​(double n, double r)
      Helper to compute the binomial coefficient.
      Parameters:
      n - number of elements in set
      r - number of elements
      Returns:
      the binomial coefficient

    • hypergeometricDistribution

      public static double hypergeometricDistribution​(double x, double N, double n, double k)
      Helper to compute the hypergeometric distribution. See this page for more information about this function.
      Parameters:
      x - x
      N - N
      n - n
      k - k
      Returns:
      hypergeometric Distribution

    • cumulativeHypergeometricDistribution

      public static double cumulativeHypergeometricDistribution​(double xStart, double xEnd, double N, double n, double k)
      Helper to compute the cumulative hypergeometric distribution. See this page for more information about this function.
      Parameters:
      xStart - xStart
      xEnd - xEnd
      N - N
      n - n
      k - k
      Returns:
      Cumulative Hypergeometric Distribution