edu.ucla.sspace.matrix

Class PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform

java.lang.Object

edu.ucla.sspace.matrix.PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform

All Implemented Interfaces:

GlobalTransform

Enclosing class:

PointWiseMutualInformationTransform

public class PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform
extends Object
implements GlobalTransform

Constructor Summary

Constructors

Constructor and Description
PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform(File inputMatrixFile, MatrixIO.Format format) Creates an instance of PointWiseMutualInformationTransform from a matrix File of format format.
PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform(Matrix matrix) Creates an instance of PointWiseMutualInformationTransform from a given Matrix.

Method Summary

Methods

Modifier and Type	Method and Description
double	transform(int row, int col, double value) Computes the point wise-mutual information between the row and col with value specifying the number of occurances of row with col.

Methods inherited from class java.lang.Object

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

Constructor Detail

PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform

public PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform(Matrix matrix)

Creates an instance of PointWiseMutualInformationTransform from a given Matrix.

PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform

public PointWiseMutualInformationTransform.PointWiseMutualInformationGlobalTransform(File inputMatrixFile,
                                                                             MatrixIO.Format format)

Creates an instance of PointWiseMutualInformationTransform from a matrix File of format format.

Method Detail

transform

public double transform(int row,
               int col,
               double value)

Computes the point wise-mutual information between the row and col with value specifying the number of occurances of row with col. This is approximated based on the occurance counts for each row and col.

Specified by:

transform in interface GlobalTransform

Parameters:

row - The index specifying the row being observed

col - The index specifying the col being observed

value - The number of ocurrances of row and col together

Returns:

log(value * matrixSum / (rowSum[row] * colSum[col]))