org.egothor.dir

Class CWI

java.lang.Object

org.egothor.dir.CWI

All Implemented Interfaces:

CWI

public class CWI
extends Object
implements CWI

The CWI object represents the simplest case of Collection-Wide-Information in an Information Retrieval system. It stores inverse document frequency idf(java.lang.String). The frequency is computed from the total number of documents in the system (it can be modified via addTotalSize(long) calling), and from the number of documents which contain a given term/word (it can be modified via addLength(java.lang.String, long) calling).

Author:

Leo Galambos

Field Summary

Fields inherited from interface org.egothor.core.CWI

IDF_UNKNOWN

Constructor Summary

Constructors

Constructor and Description
CWI() Constructor for the CWI object.

Method Summary

Modifier and Type	Method and Description
void	addLength(String term, long inc) Add the given term, which occurs in the given number of documents, to this CWI.
void	addTotalSize(long inc) Increase the number of documents in the system by the given amount.
boolean	defined(String term) Test whether CWI contains the given term.
double	idf(String term) Return the inverse document frequency for the given term.

Methods inherited from class java.lang.Object

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

Constructor Detail

CWI

public CWI()

Constructor for the CWI object.

Method Detail

defined

public boolean defined(String term)

Test whether CWI contains the given term.

Specified by:

defined in interface CWI

Parameters:

term - the term

Returns:

true if it does, false otherwise

idf

public double idf(String term)

Return the inverse document frequency for the given term.

Specified by:

idf in interface CWI

Parameters:

term - the term

Returns:

the inverse document frequency

addTotalSize

public void addTotalSize(long inc)

Increase the number of documents in the system by the given amount.

Parameters:

inc - the amount by which to increase

addLength

public void addLength(String term,
                      long inc)

Add the given term, which occurs in the given number of documents, to this CWI.

Parameters:

term - the term

inc - the number of documents in which the term appears