Package it.unimi.dsi.big.webgraph

Class Stats

java.lang.Object

it.unimi.dsi.big.webgraph.Stats

public class Stats
extends Object

Computes basic statistical data about a given graph.

This class loads a graph of given basename, and computes the following data:

1. an ASCII file containing the outdegree distribution; line n contains the number of nodes with outdegree n (starting from 0);
2. an ASCII file containing the indegree distribution; line n contains the number of nodes with indegree n (starting from 0);
3. a property file containing several self-descriptive data, such as the average indegree/outdegree (which should be identical), sample nodes with minimum or maximum indegree/outdegree, and so on; additional data will be computed if files produced by StronglyConnectedComponents are present with the same basename (in particular, buckets and component sizes);
4. if files produced by StronglyConnectedComponents are present with the same basename, an ASCII file containing the distribution of strongly connected components, specified as a sequence of lines each containing a pair of integer <size, count>.

The graph is loaded offline: the only memory allocated is for indegree count (one integer per node) and for storing the actual counts (one integer per indegree/outdegree value).

Method Summary

Modifier and Type	Method	Description
static void	main(String[] arg)
static void	run(ImmutableGraph graph, LongArrayBitVector buckets, long[][] sccsize, CharSequence resultsBasename, boolean saveDegrees, ProgressLogger pl)	Computes stats for the given graph using a single traversal, storing the results in files with given basename.
static void	run(ImmutableGraph graph, LongArrayBitVector buckets, long[][] sccsize, CharSequence resultsBasename, ProgressLogger pl)	Computes stats for the given graph using a single traversal, storing the results in files with given basename.

Methods inherited from class java.lang.Object

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

Method Details

run

public static void run(ImmutableGraph graph,
 LongArrayBitVector buckets,
 long[][] sccsize,
 CharSequence resultsBasename,
 ProgressLogger pl)
                throws IOException

Computes stats for the given graph using a single traversal, storing the results in files with given basename.

Parameters:

graph - the graph to be examined.

buckets - the set of buckets of this graph, or null if this information is not available.

sccsize - the sizes of strongly connected components as a big array, or null if this information is not available.

resultsBasename - the basename for result files (see the class description).

pl - a progress logger.

Throws:

IOException

run

public static void run(ImmutableGraph graph,
 LongArrayBitVector buckets,
 long[][] sccsize,
 CharSequence resultsBasename,
 boolean saveDegrees,
 ProgressLogger pl)
                throws IOException

Computes stats for the given graph using a single traversal, storing the results in files with given basename.

Parameters:

graph - the graph to be examined.

buckets - the set of buckets of this graph, or null if this information is not available.

sccsize - the sizes of strongly connected components as a big array, or null if this information is not available.

resultsBasename - the basename for result files (see the class description).

saveDegrees - if true, indegrees and outdegrees will be saved.

pl - a progress logger.

Throws:

IOException

main

public static void main(String[] arg)
                 throws IllegalArgumentException,
SecurityException,
IllegalAccessException,
InvocationTargetException,
NoSuchMethodException,
JSAPException,
IOException,
ClassNotFoundException

Throws:

IllegalArgumentException

SecurityException

IllegalAccessException

InvocationTargetException

NoSuchMethodException

JSAPException

IOException

ClassNotFoundException