PageRankWithPriors

java.lang.Object
- edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorer<V,E,S>
- - edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorerWithPriors<V,E,java.lang.Double>
  - - edu.uci.ics.jung.algorithms.scoring.PageRankWithPriors<V,E>

All Implemented Interfaces:

VertexScorer<V,java.lang.Double>, IterativeContext

Direct Known Subclasses:

KStepMarkov, PageRank
```
public class PageRankWithPriors<V,E>
extends AbstractIterativeScorerWithPriors<V,E,java.lang.Double>
```
A generalization of PageRank that permits non-uniformly-distributed random jumps. The 'vertex_priors' (that is, prior probabilities for each vertex) may be thought of as the fraction of the total 'potential' that is assigned to that vertex at each step out of the portion that is assigned according to random jumps (this portion is specified by 'alpha').

See Also:
"Algorithms for Estimating Relative Importance in Graphs by Scott White and Padhraic Smyth, 2003", PageRank

Field Summary

Fields
Modifier and Type Field and Description

protected double disappearing_potential
Maintains the amount of potential associated with vertices with no out-edges.
- Fields inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorerWithPriors
  alpha, vertex_priors
- Fields inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorer
  edge_weights, graph, hyperedges_are_self_loops, max_delta, max_iterations, output_reversed, tolerance, total_iterations

Fields
Modifier and Type	Field and Description
`protected double`	`disappearing_potential` Maintains the amount of potential associated with vertices with no out-edges.

Constructor Summary

Constructors
Constructor and Description
`PageRankWithPriors(edu.uci.ics.jung.graph.Hypergraph<V,E> graph, org.apache.commons.collections4.Transformer<E,? extends java.lang.Number> edge_weights, org.apache.commons.collections4.Transformer<V,java.lang.Double> vertex_priors, double alpha)` Creates an instance with the specified graph, edge weights, vertex priors, and 'random jump' probability (alpha).
`PageRankWithPriors(edu.uci.ics.jung.graph.Hypergraph<V,E> graph, org.apache.commons.collections4.Transformer<V,java.lang.Double> vertex_priors, double alpha)` Creates an instance with the specified graph, vertex priors, and 'random jump' probability (alpha).

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`afterStep()` Cleans up after each step.
`protected void`	`collectDisappearingPotential(V v)` Collects the "disappearing potential" associated with vertices that have no outgoing edges.
`double`	`update(V v)` Updates the value for this vertex.

Methods inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorerWithPriors
getAlpha, getVertexPrior, getVertexPriors, initialize

Methods inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorer
acceptDisconnectedGraph, done, evaluate, getAdjustedIncidentCount, getCurrentValue, getEdgeWeight, getEdgeWeights, getIterations, getMaxIterations, getOutputValue, getTolerance, getVertexScore, isDisconnectedGraphOK, setCurrentValue, setEdgeWeights, setHyperedgesAreSelfLoops, setMaxIterations, setOutputValue, setTolerance, step, swapOutputForCurrent, updateMaxDelta

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface edu.uci.ics.jung.algorithms.scoring.VertexScorer
getVertexScore

- Field Detail
  - disappearing_potential
```
protected double disappearing_potential
```
    Maintains the amount of potential associated with vertices with no out-edges.
- Constructor Detail
  - PageRankWithPriors
```
public PageRankWithPriors(edu.uci.ics.jung.graph.Hypergraph<V,E> graph,
                  org.apache.commons.collections4.Transformer<E,? extends java.lang.Number> edge_weights,
                  org.apache.commons.collections4.Transformer<V,java.lang.Double> vertex_priors,
                  double alpha)
```
    Creates an instance with the specified graph, edge weights, vertex priors, and 'random jump' probability (alpha).
    
    Parameters:
    graph - the input graph
    edge_weights - the edge weights, denoting transition probabilities from source to destination
    vertex_priors - the prior probabilities for each vertex
    alpha - the probability of executing a 'random jump' at each step
  - PageRankWithPriors
```
public PageRankWithPriors(edu.uci.ics.jung.graph.Hypergraph<V,E> graph,
                  org.apache.commons.collections4.Transformer<V,java.lang.Double> vertex_priors,
                  double alpha)
```
    Creates an instance with the specified graph, vertex priors, and 'random jump' probability (alpha). The outgoing edge weights for each vertex will be equal and sum to 1.
    
    Parameters:
    graph - the input graph
    vertex_priors - the prior probabilities for each vertex
    alpha - the probability of executing a 'random jump' at each step
- Method Detail
  - update
```
public double update(V v)
```
    Updates the value for this vertex. Called by step().
    
    Specified by:
    
    update in class AbstractIterativeScorer<V,E,java.lang.Double>
    
    Parameters:
    v - the vertex whose value is to be updated
    
    Returns:
  - afterStep
```
protected void afterStep()
```
    Cleans up after each step. In this case that involves allocating the disappearing potential (thus maintaining normalization of the scores) according to the vertex probability priors, and then calling super.afterStep.
    
    Overrides:
    
    afterStep in class AbstractIterativeScorer<V,E,java.lang.Double>
  - collectDisappearingPotential
```
protected void collectDisappearingPotential(V v)
```
    Collects the "disappearing potential" associated with vertices that have no outgoing edges. Vertices that have no outgoing edges do not directly contribute to the scores of other vertices. These values are collected at each step and then distributed across all vertices as a part of the normalization process.
    
    Overrides:
    
    collectDisappearingPotential in class AbstractIterativeScorer<V,E,java.lang.Double>

Class PageRankWithPriors<V,E>

Field Summary

Fields inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorerWithPriors

Fields inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorer

Constructor Summary

Method Summary

Methods inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorerWithPriors

Methods inherited from class edu.uci.ics.jung.algorithms.scoring.AbstractIterativeScorer

Methods inherited from class java.lang.Object

Methods inherited from interface edu.uci.ics.jung.algorithms.scoring.VertexScorer

Field Detail

disappearing_potential

Constructor Detail

PageRankWithPriors

PageRankWithPriors

Method Detail

update

afterStep

collectDisappearingPotential