PageRank

An implementation of the pagerank algorithm in Node.js

Setup

npm install package-js

Technical tutorial

The code/tutorial for this library, created with docco, explains the theory behind pagerank and shows how this library works!

Usage

This example corresponds to 6 nodes with each array representing outgoing edges

nodes = [1,2],[],[0,1,4],[4,5],[3,5],[3]
linkProb = 0.85 //high numbers are more stable
tolerance = 0.0001 //sensitivity for accuracy of convergence. 

Pagerank(nodes, linkProb, tolerance, function (err, res) {
    if (err) throw new Error(err)
    
    //otherwise use the result (res)
})

Testing

npm test

Results

For the dataset provided above (6 pages)

____ITERATION 0____
[ 0.14285714285714285,
  0.14285714285714285,
  0.14285714285714285,
  0.14285714285714285,
  0.14285714285714285,
  0.14285714285714285,
  0.14285714285714285 ]
____ITERATION 1____
[ 0.18333333333333332,
  0.17726190476190476,
  0.15747916666666667,
  0.1874762400793651,
  0.1457250706845238,
  0.1011059734623016,
  0.12633176519097222 ]
____ITERATION 2____
[ 0.18435401689608136,
  0.1781294857902406,
  0.1590667579303463,
  0.17387948658782926,
  0.1403962679753303,
  0.09532735322839887,
  0.12161111044015634 ]
____ITERATION 3____
[ 0.18271664275842467,
  0.1767377177732324,
  0.1562105153717106,
  0.169057661324689,
  0.13753772351354893,
  0.09327807749156426,
  0.11952528685574454 ]
____ITERATION 4____
[ 0.18044493043809468,
  0.1748067623009519,
  0.15417497789973428,
  0.166707975660879,
  0.1359623714893697,
  0.09227946108444501,
  0.11843135027244268 ]
____ITERATION 5____
[ 0.17862312677228984,
  0.1732582291850178,
  0.1528473267151861,
  0.16540196172945043,
  0.1350311477328906,
  0.09172440516358786,
  0.11779968140957478 ]
____ITERATION 6____
[ 0.17735293359603158,
  0.17217856498519826,
  0.1519926993337592,
  0.1646228987712751,
  0.13445790155092846,
  0.09139330340636334,
  0.11741533353542045 ]
____ITERATION 7____
[ 0.1765112136395502,
  0.1714631030221891,
  0.1514449983721464,
  0.1641410211391203,
  0.13409792161813902,
  0.09118850541269756,
  0.11717530291667698 ]
____ITERATION 8____
[ 0.17596492121883975,
  0.1709987544645852,
  0.15109465876372924,
  0.16383773222413683,
  0.13386976094021952,
  0.09105960762382959,
  0.1170235530682923 ]
____ITERATION 9____
[ 0.17561352863253768,
  0.17070007076622845,
  0.15087074990381183,
  0.16364530400936658,
  0.1337245381052989,
  0.09097782563255223,
  0.11692707601715817 ]
____ITERATION 10____
[ 0.1753883898707999,
  0.17050870281875136,
  0.15072769882129278,
  0.1635227673758555,
  0.13363192889600964,
  0.09092574756331002,
  0.1168655839237823 ]
____ITERATION 11____
[ 0.17524439417364712,
  0.17038630647617148,
  0.1506363214617484,
  0.1634446088446151,
  0.13357282126836156,
  0.09089253018753285,
  0.11682634579732656 ]
____RESULTS____
[ 0.1751523680914745,
  0.17030808430632474,
  0.1505779562978131,
  0.1633947196406794,
  0.13353508156024055,
  0.09087132727586017,
  0.11680129518391424 ]