edu.ucla.sspace.matrix

Class TfIdfTransform

java.lang.Object

edu.ucla.sspace.matrix.BaseTransform

edu.ucla.sspace.matrix.TfIdfTransform

All Implemented Interfaces:

Transform

public class TfIdfTransform
extends BaseTransform

Tranforms a matrix according to the Term frequency-Inverse Document Frequency weighting. The input matrix is assumed to be formatted as rows representing terms and columns representing documents. Each matrix cell indicates the number of times the row's word occurs within the column's document. For full details see:

• Spärck Jones, Karen (1972). "A statistical interpretation of term specificity and its application in retrieval". Journal of Documentation 28 (1): 11–21.

Author:

David Jurgens

See Also:

LogEntropyTransform

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	TfIdfTransform.TfIdfGlobalTransform

Constructor Summary

Constructors

Constructor and Description
TfIdfTransform()

Method Summary

Methods

Modifier and Type	Method and Description
protected GlobalTransform	getTransform(File inputMatrixFile, MatrixIO.Format format) Returns a GlobalTransform for a File of the given format.
protected GlobalTransform	getTransform(Matrix matrix) Returns a GlobalTransform for a Matrix.
String	toString() Returns the name of this transform.

Methods inherited from class edu.ucla.sspace.matrix.BaseTransform

transform, transform, transform, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

TfIdfTransform

public TfIdfTransform()

Method Detail

getTransform

protected GlobalTransform getTransform(Matrix matrix)

Returns a GlobalTransform for a Matrix.

Specified by:

getTransform in class BaseTransform

getTransform

protected GlobalTransform getTransform(File inputMatrixFile,
                           MatrixIO.Format format)

Returns a GlobalTransform for a File of the given format.

Specified by:

getTransform in class BaseTransform

toString

public String toString()

Returns the name of this transform.

Overrides:

toString in class Object