Package elki.distance

Class CanberraDistance

java.lang.Object

elki.distance.CanberraDistance

All Implemented Interfaces:

Distance<NumberVector>, NumberVectorDistance<NumberVector>, PrimitiveDistance<NumberVector>, SpatialPrimitiveDistance<NumberVector>

@Priority(200)
@Reference(authors="G. N. Lance, W. T. Williams",
           title="Computer Programs for Hierarchical Polythetic Classification (Similarity Analyses)",
           booktitle="Computer Journal, Volume 9, Issue 1",
           url="https://doi.org/10.1093/comjnl/9.1.60",
           bibkey="doi:10.1093/comjnl/9.1.60")
@Alias("canberra")
public class CanberraDistance
extends java.lang.Object
implements SpatialPrimitiveDistance<NumberVector>, NumberVectorDistance<NumberVector>

Canberra distance function, a variation of Manhattan distance.

Canberra distance is defined as: \[ \text{Canberra}(\vec{x},\vec{y}) := \sum\nolimits_i \tfrac{|x_i-y_i|}{|x_i|+|y_i|} \]

Reference:
G. N. Lance, W. T. Williams
Computer Programs for Hierarchical Polythetic Classification ("Similarity Analyses")
In: Computer Journal, Volume 9, Issue 1

Since:

0.5.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CanberraDistance.Par	Parameterization class.

Field Summary

Fields

Modifier and Type	Field	Description
static CanberraDistance	STATIC	Static instance.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CanberraDistance()	Constructor.

Method Summary

Modifier and Type	Method	Description
double	distance(NumberVector v1, NumberVector v2)	Computes the distance between two given DatabaseObjects according to this distance function.
boolean	equals(java.lang.Object obj)
SimpleTypeInformation<? super NumberVector>	getInputTypeRestriction()	Get the input data type of the function.
int	hashCode()
boolean	isMetric()	Is this distance function metric (satisfy the triangle inequality)
double	minDist(SpatialComparable mbr1, SpatialComparable mbr2)	Computes the distance between the two given MBRs according to this distance function.

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.distance.Distance

isSquared, isSymmetric

Methods inherited from interface elki.distance.SpatialPrimitiveDistance

instantiate

Field Detail

STATIC

public static final CanberraDistance STATIC

Static instance. Use this!

Constructor Detail

CanberraDistance

protected CanberraDistance()

Constructor.

Method Detail

distance

public double distance(NumberVector v1,
                       NumberVector v2)

Description copied from interface: PrimitiveDistance

Computes the distance between two given DatabaseObjects according to this distance function.

Specified by:

distance in interface NumberVectorDistance<NumberVector>

Specified by:

distance in interface PrimitiveDistance<NumberVector>

Parameters:

v1 - first DatabaseObject

v2 - second DatabaseObject

Returns:

the distance between two given DatabaseObjects according to this distance function

minDist

public double minDist(SpatialComparable mbr1,
                      SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDistance

Computes the distance between the two given MBRs according to this distance function.

Specified by:

minDist in interface SpatialPrimitiveDistance<NumberVector>

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the two given MBRs according to this distance function

isMetric

public boolean isMetric()

Description copied from interface: Distance

Is this distance function metric (satisfy the triangle inequality)

Specified by:

isMetric in interface Distance<NumberVector>

Returns:

true when metric.

getInputTypeRestriction

public SimpleTypeInformation<? super NumberVector> getInputTypeRestriction()

Description copied from interface: Distance

Get the input data type of the function.

Specified by:

getInputTypeRestriction in interface Distance<NumberVector>

Specified by:

getInputTypeRestriction in interface PrimitiveDistance<NumberVector>

Returns:

Type restriction

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object