com.eatthepath.jvptree.util

Class SamplingMedianDistanceThresholdSelectionStrategy<P,E extends P>

java.lang.Object

com.eatthepath.jvptree.util.MedianDistanceThresholdSelectionStrategy<P,E>

com.eatthepath.jvptree.util.SamplingMedianDistanceThresholdSelectionStrategy<P,E>

All Implemented Interfaces:

ThresholdSelectionStrategy<P,E>

public class SamplingMedianDistanceThresholdSelectionStrategy<P,E extends P>
extends MedianDistanceThresholdSelectionStrategy<P,E>
implements ThresholdSelectionStrategy<P,E>

A threshold distance selection strategy that uses the median distance from the origin to a subset of the given list of points as the threshold.

Author:

Jon Chambers

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_NUMBER_OF_SAMPLES

Constructor Summary

Constructors

Constructor and Description
SamplingMedianDistanceThresholdSelectionStrategy(int numberOfSamples) Constructs a threshold selector that uses up to the given number of samples from a list of points to choose a median distance.

Method Summary

Modifier and Type	Method and Description
double	selectThreshold(List<E> points, P origin, DistanceFunction<P> distanceFunction) Returns the median distance of a subset of the given points from the given origin.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_NUMBER_OF_SAMPLES

public static final int DEFAULT_NUMBER_OF_SAMPLES

See Also:

Constant Field Values

Constructor Detail

SamplingMedianDistanceThresholdSelectionStrategy

public SamplingMedianDistanceThresholdSelectionStrategy(int numberOfSamples)

Constructs a threshold selector that uses up to the given number of samples from a list of points to choose a median distance.

Parameters:

numberOfSamples - the maximum number of samples to use when choosing a median distance

Method Detail

selectThreshold

public double selectThreshold(List<E> points,
                              P origin,
                              DistanceFunction<P> distanceFunction)

Returns the median distance of a subset of the given points from the given origin. The given list of points may be partially sorted in the process.

Specified by:

selectThreshold in interface ThresholdSelectionStrategy<P,E extends P>

Overrides:

selectThreshold in class MedianDistanceThresholdSelectionStrategy<P,E extends P>

Parameters:

points - the list of points from which a median distance will be chosen

origin - the point from which distances to other points will be calculated

distanceFunction - the function to be used to calculate the distance between the origin and other points

Returns:

the median distance from the origin to the given list of points