edu.uci.ics.jung.algorithms.importance
Class HITS

java.lang.Object
  edu.uci.ics.jung.algorithms.IterativeProcess
      edu.uci.ics.jung.algorithms.importance.AbstractRanker
          edu.uci.ics.jung.algorithms.importance.HITS

public class HITS

extends AbstractRanker

Calculates the "hubs-and-authorities" importance measures for each node in a graph. These measures are defined recursively as follows:

• The *hubness* of a node is the degree to which a node links to other important authorities
• The *authoritativeness* of a node is the degree to which a node is pointed to by important hubs

Note: This algorithm uses the same key as HITSWithPriors for storing rank sccores.

A simple example of usage is:

 HITS ranker = new HITS(someGraph);
 ranker.evaluate();
 ranker.printRankings();
 

Running time: O(|V|*I) where |V| is the number of vertices and I is the number of iterations until convergence

Author:

Scott White

See Also:

"Authoritative sources in a hyperlinked environment by Jon Kleinberg, 1997"

Field Summary

Fields inherited from class edu.uci.ics.jung.algorithms.importance.AbstractRanker

DEFAULT_EDGE_WEIGHT_KEY

Constructor Summary

HITS(Graph graph)
Constructs an instance of the ranker where the type of importance that is associated with the rank score is the node's importance as an authority.

HITS(Graph graph, boolean useAuthorityForRanking)
Constructs an instance of the ranker where the type of importance that is associated with the rank score is the node's importance as an authority.

Method Summary

double	getRankScore(UserDataContainer v) Given a node, returns the corresponding rank score.
java.lang.String	getRankScoreKey() the user datum key used to store the rank scores
void	setUseAuthorityForRanking(boolean useAuthorityForRanking) If evaluate() has not already been called, the user can override the type of importance.

Methods inherited from class edu.uci.ics.jung.algorithms.importance.AbstractRanker

getEdgeWeightKeyName, getRankings, getRankScores, isRankingNodes, printRankings, setNormalizeRankings, setRemoveRankScoresOnFinalize, setUserDefinedEdgeWeightKey

Methods inherited from class edu.uci.ics.jung.algorithms.IterativeProcess

evaluate, getDesiredPrecision, getIterations, getMaximumIterations, getPrecision, hasConverged, relativePrecision, setDesiredPrecision, setMaximumIterations

Methods inherited from class java.lang.Object

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

Constructor Detail

HITS

public HITS(Graph graph,
            boolean useAuthorityForRanking)

Constructs an instance of the ranker where the type of importance that is associated with the rank score is the node's importance as an authority.

Parameters:

graph - the graph whose nodes are to be ranked

useAuthorityForRanking -

HITS

public HITS(Graph graph)

Constructs an instance of the ranker where the type of importance that is associated with the rank score is the node's importance as an authority.

Parameters:

graph - the graph whose nodes are to be ranked

Method Detail

getRankScoreKey

public java.lang.String getRankScoreKey()

the user datum key used to store the rank scores

Specified by:

getRankScoreKey in class AbstractRanker

Returns:

the key

getRankScore

public double getRankScore(UserDataContainer v)

Given a node, returns the corresponding rank score. This implementation of getRankScore assumes the decoration representing the rank score is of type MutableDouble.

Overrides:

getRankScore in class AbstractRanker

Returns:

the rank score for this node

setUseAuthorityForRanking

public void setUseAuthorityForRanking(boolean useAuthorityForRanking)

If evaluate() has not already been called, the user can override the type of importance. (hub or authority) that should be associated with the rank score.

Parameters:

useAuthorityForRanking - if true, authority is used; if false, hub is used