uk.ac.gla.terrier.structures
Class CollectionStatistics

java.lang.Object
  uk.ac.gla.terrier.structures.CollectionStatistics

public class CollectionStatistics
extends java.lang.Object

This class provides basic statistics for the indexed collection of documents, such as the average length of documents, or the total number of documents in the collection.
After indexing, statistics are saved in the PREFIX.log file, along with the classes that should be used for the Lexicon, the DocumentIndex, the DirectIndex and the InvertedIndex. This means that an index knows how it was build and how it should be opened again.

Version:

$Revision: 1.32 $

Author:

Gianni Amati, Vassilis Plachouras, Craig Macdonald

Constructor Summary

CollectionStatistics(int numDocs, int numTerms, long numTokens, long numPointers)

Method Summary

double	getAverageDocumentLength() Returns the documents' average length.
int	getNumberOfDocuments() Returns the total number of documents in the collection.
long	getNumberOfPointers() Returns the total number of pointers in the collection.
long	getNumberOfTokens() Returns the total number of tokens in the collection.
int	getNumberOfUniqueTerms() Returns the total number of unique terms in the lexicon.

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionStatistics

public CollectionStatistics(int numDocs,
                            int numTerms,
                            long numTokens,
                            long numPointers)

Method Detail

getAverageDocumentLength

public double getAverageDocumentLength()

Returns the documents' average length.

Returns:

the average length of the documents in the collection.

getNumberOfDocuments

public int getNumberOfDocuments()

Returns the total number of documents in the collection.

Returns:

the total number of documents in the collection

getNumberOfPointers

public long getNumberOfPointers()

Returns the total number of pointers in the collection.

Returns:

the total number of pointers in the collection

getNumberOfTokens

public long getNumberOfTokens()

Returns the total number of tokens in the collection.

Returns:

the total number of tokens in the collection

getNumberOfUniqueTerms

public int getNumberOfUniqueTerms()

Returns the total number of unique terms in the lexicon.

Returns:

the total number of unique terms in the lexicon