Package elki.distance.probabilistic
Class ChiDistance
- java.lang.Object
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- elki.distance.AbstractNumberVectorDistance
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- elki.distance.probabilistic.ChiSquaredDistance
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- elki.distance.probabilistic.ChiDistance
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- All Implemented Interfaces:
Distance<NumberVector>
,NumberVectorDistance<NumberVector>
,PrimitiveDistance<NumberVector>
,SpatialPrimitiveDistance<NumberVector>
@Alias("chi") @Priority(100) @Reference(authors="J. Puzicha, J. M. Buhmann, Y. Rubner, C. Tomasi",title="Empirical evaluation of dissimilarity measures for color and texture",booktitle="Proc. 7th IEEE International Conference on Computer Vision",url="https://doi.org/10.1109/ICCV.1999.790412",bibkey="DBLP:conf/iccv/PuzichaRTB99") @Reference(authors="D. M. Endres, J. E. Schindelin",title="A new metric for probability distributions",booktitle="IEEE Transactions on Information Theory 49(7)",url="https://doi.org/10.1109/TIT.2003.813506",bibkey="DBLP:journals/tit/EndresS03") public class ChiDistance extends ChiSquaredDistance
χ distance function, symmetric version. This is the square root of theChiSquaredDistance
, and can serve as a fast approximation toSqrtJensenShannonDivergenceDistance
.This implementation assumes \(\sum_i x_i=\sum_i y_i\), and is defined as: \[ \chi(\vec{x},\vec{y}):= \sqrt{2 \sum\nolimits_i \tfrac{(x_i-x_i)^2}{x_i+y_i}} \]
Reference:
J. Puzicha, J. M. Buhmann, Y. Rubner, C. Tomasi
Empirical evaluation of dissimilarity measures for color and texture
Proc. 7th IEEE International Conference on Computer VisionD. M. Endres, J. E. Schindelin
A new metric for probability distributions
IEEE Transactions on Information Theory 49(7)- Since:
- 0.7.5
- Author:
- Erich Schubert
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ChiDistance.Par
Parameterization class, using the static instance.
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Field Summary
Fields Modifier and Type Field Description static ChiDistance
STATIC
Static instance.
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Constructor Summary
Constructors Constructor Description ChiDistance()
Deprecated.Use static instance!
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description double
distance(NumberVector v1, NumberVector v2)
Computes the distance between two given DatabaseObjects according to this distance function.boolean
isMetric()
Is this distance function metric (satisfy the triangle inequality)boolean
isSquared()
Squared distances, that would become metric after square root.double
minDist(SpatialComparable mbr1, SpatialComparable mbr2)
Computes the distance between the two given MBRs according to this distance function.java.lang.String
toString()
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Methods inherited from class elki.distance.probabilistic.ChiSquaredDistance
equals, getInputTypeRestriction, hashCode
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Methods inherited from class elki.distance.AbstractNumberVectorDistance
dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface elki.distance.Distance
isSymmetric
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Methods inherited from interface elki.distance.SpatialPrimitiveDistance
instantiate
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Field Detail
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STATIC
public static final ChiDistance STATIC
Static instance. Use this!
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Method Detail
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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 interfaceNumberVectorDistance<NumberVector>
- Specified by:
distance
in interfacePrimitiveDistance<NumberVector>
- Overrides:
distance
in classChiSquaredDistance
- Parameters:
v1
- first DatabaseObjectv2
- second DatabaseObject- Returns:
- the distance between two given DatabaseObjects according to this distance function
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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 interfaceSpatialPrimitiveDistance<NumberVector>
- Overrides:
minDist
in classChiSquaredDistance
- Parameters:
mbr1
- the first MBR objectmbr2
- the second MBR object- Returns:
- the distance between the two given MBRs according to this distance function
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isMetric
public boolean isMetric()
Description copied from interface:Distance
Is this distance function metric (satisfy the triangle inequality)- Returns:
true
when metric.
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isSquared
public boolean isSquared()
Description copied from interface:Distance
Squared distances, that would become metric after square root.E.g. squared Euclidean.
- Specified by:
isSquared
in interfaceDistance<NumberVector>
- Overrides:
isSquared
in classChiSquaredDistance
- Returns:
true
when squared.
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toString
public java.lang.String toString()
- Overrides:
toString
in classChiSquaredDistance
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