ivory.ffg.data

Class DocumentVectorHashedArray

java.lang.Object

ivory.ffg.data.DocumentVectorHashedArray

All Implemented Interfaces:

DocumentVector, Writable

public class DocumentVectorHashedArray
extends Object
implements DocumentVector

Document vector representation using the hashing technique described in \cite{sigir2011 submission}.

Author:

Nima Asadi

Method Summary

Methods

Modifier and Type	Method and Description
int[]	decompressDocument() Decompresses the document vector into a flat array representation
int[][]	decompressPositions(int[] terms) Decompresses/constructs positions.
boolean	equals(Object o)
int	getDocumentLength()
static DocumentVectorHashedArray	newInstance(int[] document) Creates an instance of this class by transforming the given document vector into the new (hashed) space.
void	readFields(DataInput input)
static DocumentVectorHashedArray	readInstance(DataInput input) Reads and returns a document vector from input
int[]	transformTerms(int[] terms) Transforms query terms
void	write(DataOutput output)

Methods inherited from class java.lang.Object

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

Method Detail

decompressDocument

public int[] decompressDocument()
                         throws IOException

Description copied from interface: DocumentVector

Decompresses the document vector into a flat array representation

Specified by:

decompressDocument in interface DocumentVector

Returns:

Decompressed flat array representation of the document vector

Throws:

IOException

decompressPositions

public int[][] decompressPositions(int[] terms)
                            throws IOException

Description copied from interface: DocumentVector

Decompresses/constructs positions. This method applies the necessary transformation functions tot he input query terms.

Specified by:

decompressPositions in interface DocumentVector

Parameters:

terms - Query terms

Returns:

Position arrays for every term in the query

Throws:

IOException

equals

public boolean equals(Object o)

Overrides:

equals in class Object

getDocumentLength

public int getDocumentLength()

Specified by:

getDocumentLength in interface DocumentVector

Returns:

Length of this document

newInstance

public static DocumentVectorHashedArray newInstance(int[] document)

Creates an instance of this class by transforming the given document vector into the new (hashed) space.

Parameters:

document - Input document vector.

Returns:

Transformed document vector and the hash function.

readFields

public void readFields(DataInput input)
                throws IOException

Specified by:

readFields in interface Writable

Throws:

IOException

readInstance

public static DocumentVectorHashedArray readInstance(DataInput input)
                                              throws IOException

Reads and returns a document vector from input

Parameters:

input - DataInput

Returns:

A document vector

Throws:

IOException

transformTerms

public int[] transformTerms(int[] terms)

Description copied from interface: DocumentVector

Transforms query terms

Specified by:

transformTerms in interface DocumentVector

Parameters:

terms - Query terms

Returns:

Transformed query terms

write

public void write(DataOutput output)
           throws IOException

Specified by:

write in interface Writable

Throws:

IOException