edu.stanford.math.plex

Class RDirectBufferData

java.lang.Object

edu.stanford.math.plex.PointData

edu.stanford.math.plex.RDirectBufferData

public class RDirectBufferData
extends PointData

The RDirectBufferData is a mechanism for transforming an R distance matrix into a PointData.

Version:

$Id$

Nested Class Summary

Nested classes/interfaces inherited from class edu.stanford.math.plex.PointData

PointData.Discrete, PointData.NSpace, PointData.Predicate

Field Summary

Fields

Modifier and Type	Field and Description
protected java.nio.DoubleBuffer	distanceBuffer
protected int	p_max Max number of points.

Fields inherited from class edu.stanford.math.plex.PointData

rand

Constructor Summary

Constructors

Constructor and Description
RDirectBufferData(int count, java.nio.ByteBuffer buf) Use a pre-allocated buffer of doubles as the distance matrix.

Method Summary

Methods

Modifier and Type	Method and Description
int	count() The number of points in this data set.
double	distance(int p1, int p2) Return the distance between the two points using the external data, which is stored as 0-based columns.

Methods inherited from class edu.stanford.math.plex.PointData

random_points

Methods inherited from class java.lang.Object

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

Field Detail

p_max

protected final int p_max

Max number of points.

distanceBuffer

protected final java.nio.DoubleBuffer distanceBuffer

Constructor Detail

RDirectBufferData

public RDirectBufferData(int count,
                 java.nio.ByteBuffer buf)

Use a pre-allocated buffer of doubles as the distance matrix. The ByteBuffer passed to the constructor will be viewed as a DoubleBuffer, which will let us use the capacity function to get the max entry.

Parameters:

count - The upper bound on i. i is 1-indexed

buf - ByteBuffer instance to be used.

Method Detail

distance

public double distance(int p1,
              int p2)

Return the distance between the two points using the external data, which is stored as 0-based columns.

Specified by:

distance in class PointData

Parameters:

p1 - the first point

p2 - the second point

Returns:

the distance between p1 and p2

count

public int count()

Description copied from class: PointData

The number of points in this data set.

Indexing begins from 1, not 0, which means that the points go from 1 to count(), inclusive. It is acceptable for an implementation to allow points to be added.

Specified by:

count in class PointData

Returns:

The number of points in the data set.