Trustrank in Java (using webgraph)

Trustrank is a biased PageRank method, which starts from some good seeds to propagate trust. It is very easy to implement based on PageRank.

I implement it in Java using the webgraph and Law jar package, following is the code:

 
/*
 
 
* Trustrank implement
 
 
*/
 
 
PackageCn.edu. dlut. wisdom;
 
 
 
ImportIt. unimi. DSI. law. Rank. PageRank;
 
 
ImportIt. unimi. DSI. law. Rank. pagerankpowermethod;
 
 
ImportIt. unimi. DSI. law. Rank. PageRank. iterationnumberstoppingcriterion;
 
ImportIt. unimi. DSI. law. Rank. PageRank. normdeltastoppingcriterion;
 
 
 
 
ImportIt. unimi. DSI. webgraph .*;
 
 
ImportIt. unimi. DSI. fastutil. Doubles .*;
 
ImportIt. unimi. DSI. fastutil. ints. intset;
 
 
 
 
/**
 
 
*
 
 
* @ Author you Wang
 
*/
 
 
Public ClassTrustrank {
 
 
 
 
/**
 
 
* Graph on which tr will run
 
*/
 
 
PrivateImmutablegraph g;
 
 
/**
 
 
* PageRank implementation
 
 
*/
 
PrivatePagerankpowermethod PR;
 
 
/**
 
 
* To be used as stopping Criterion
 
 
*/
 
Private DoubleThreshold = PageRank. default_threshold;
 
 
/**
 
 
* Number of iteration
 
 
*/
 
Private IntNumberofiteration = PageRank. default_max_iter;
 
 
 
 
Private DoubleAlpha = PageRank. default_alpha;
 
 
 
/**
 
 
*
 
 
* @ Param g graph on which tr will run
 
 
*/
 
 
PublicTrustrank (immutablegraph g ){
 
This. G = g;
 
 
PR =NewPagerankpowermethod (g );
 
 
 
 
}
 
 
 
Public VoidSetthreshold (DoubleT ){
 
 
Threshold = T;
 
 
}
 
 
 
Public VoidSetalpha (DoubleAlpha ){
 
 
This. Alpha = Alpha;
 
 
}
 
 
 
Public VoidSetiteration (IntN ){
 
 
Numberofiteration = N;
 
 
}
 
 
 
Public Double[] Getrank (){
 
 
ReturnPr. rank;
 
 
}
 
 
 
 
/**
 
* Set the biased good seeds
 
 
* @ Param Seeds
 
 
*/
 
 
Public VoidSetgoodseeds (intset seeds ){
 
 
IntNumnodes = G. numnodes ();
 
Double[] Arr =New Double[Numnodes];
 
 
IntSeedsize = seeds. Size ();
 
 
For(IntI = 0; I <numnodes; I ++)
 
 
If(Seeds. Contains (I ))
 
Arr [I] = 1/seedsize;
 
 
Pr. Start = doublearraylist. Wrap (ARR );
 
 
}
 
 
 
 
/**
 
* Compute the tr scores
 
 
* @ Throws exception
 
 
*/
 
 
Public VoidCompute ()ThrowsException {
 
 
Pr. Alpha = Alpha;
 
Pr. stepuntil (PageRank. Or (NewNormdeltastoppingcriterion (threshold ),
 
 
NewIterationnumberstoppingcriterion (numberofiteration )));
 
 
}
 
 
}
 
 
 
 If you hava any question, please just put a review, or contact me by e-mail.