ocvolume.vq
Class centroid

java.lang.Object
  |
  +--ocvolume.vq.point
        |
        +--ocvolume.vq.centroid

public class centroid

extends point

last updated on June 15, 2002
description: centroid of a codebook calls: point
called by: codebook
input: k-dimensional points
output: distortion measure

Field Summary

protected double	distortion distortion measure - sum of all points' distances from the centroid
protected java.util.Vector	pts stores the points that belong to this centroid or cell
protected int	total_pts total number of points that belong to this centroid or cell

Fields inherited from class ocvolume.vq.point

coordinates, dimension

Constructor Summary

centroid(double[] Co)
constructor to create a centroid from input coordinates
calls: none
called by: codebook

Method Summary

void	add(point pt, double dist) add point to centroid's cell calls: none called by: codebook
double	getDistortion() returns the distortion measure of the current cell calls: none called by: codebook
int	getNumPts() returns the number of points in this cell calls: none called by: codebook
point	getPoint(int index) get a point at specified index calls: none called by: codebook
void	remove(point pt, double dist) removes a given point from the centroid's cell calls: none called by: codebook
void	update() update centroid by taking average of all points in the cell calls: none called by: codebook

Methods inherited from class ocvolume.vq.point

changeCo, equals, getAllCo, getCo, getDimension, setCo

Methods inherited from class java.lang.Object

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

Field Detail

distortion

protected double distortion

distortion measure - sum of all points' distances from the centroid

pts

protected java.util.Vector pts

stores the points that belong to this centroid or cell

total_pts

protected int total_pts

total number of points that belong to this centroid or cell

Constructor Detail

centroid

public centroid(double[] Co)

constructor to create a centroid from input coordinates
calls: none
called by: codebook

Parameters:

Co - coordinates array

Method Detail

getPoint

public point getPoint(int index)

get a point at specified index
calls: none
called by: codebook

Parameters:

index - index number

Returns:

the point at the specified index

getNumPts

public int getNumPts()

returns the number of points in this cell
calls: none
called by: codebook

Returns:

number of points

remove

public void remove(point pt,
                   double dist)

removes a given point from the centroid's cell
calls: none
called by: codebook

Parameters:

pt - the point to be removed

dist - distance from the centroid

add

public void add(point pt,
                double dist)

add point to centroid's cell
calls: none
called by: codebook

Parameters:

pt - a point belonging to the centroid

dist - distance from the centroid

update

public void update()

update centroid by taking average of all points in the cell
calls: none
called by: codebook

getDistortion

public double getDistortion()

returns the distortion measure of the current cell
calls: none
called by: codebook

Returns:

distortion of current cell