Package it.unimi.dsi.law.rank

Class PageRankFromCoefficients

java.lang.Object

it.unimi.dsi.law.rank.PageRankFromCoefficients

public class PageRankFromCoefficients
extends Object

Computes PageRank using its power series.

This class uses the vectors of coefficients of the PageRank power series computed optionally by PageRankPowerSeries to approximate PageRank and any of its derivatives for a given value of the damping factor α. The computation is based on the results described in “PageRank: Functional dependencies”, by Paolo Boldi, Massimo Santini, and Sebastiano Vigna, ACM Trans. Inf. Sys., 27(4):1−23, 2009.

Constructor Summary

Constructors

Constructor	Description
PageRankFromCoefficients()

Method Summary

Modifier and Type	Method	Description
static void	compute(String coeffBasename, int numCoeff, String rankBasename, double[] alpha, int[] order)	Computes PageRank and its derivatives for given damping factor values.
static void	main(String[] arg)

Methods inherited from class java.lang.Object

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

Constructor Details

PageRankFromCoefficients

public PageRankFromCoefficients()

Method Details

compute

public static void compute(String coeffBasename,
int numCoeff,
String rankBasename,
double[] alpha,
int[] order)
                    throws IOException

Computes PageRank and its derivatives for given damping factor values.

For each pair of damping factor and derivative order passed to this method, a suitable rank file will be generated. Information about the precision guarantee will be logged.

Parameters:

coeffBasename - the basename of coefficient files (as computed by PageRankPowerSeries); the actual names are obtained appending -i for the i-th coefficient.

numCoeff - the number of coefficient files.

rankBasename - the basename of the computed ranks.

alpha - an array of values of the damping factor, one for each rank to compute.

order - an array of derivative orders (0 means PageRank), parallel to alpha.

Throws:

IOException

main

public static void main(String[] arg)
                 throws IOException,
JSAPException

Throws:

IOException

JSAPException