## Class SquaredPearsonCorrelationDistance

• All Implemented Interfaces:
Distance<NumberVector>, NumberVectorDistance<NumberVector>, PrimitiveDistance<NumberVector>

public class SquaredPearsonCorrelationDistance
extends AbstractNumberVectorDistance
Squared Pearson correlation distance function for feature vectors.

The squared Pearson correlation distance is computed from the Pearson correlation coefficient $$r$$ as: $$1-r^2$$. Hence, possible values of this distance are between 0 and 1.

The distance between two vectors will be low (near 0), if their attribute values are dimension-wise strictly positively or negatively correlated. For features with uncorrelated attributes, the distance value will be high (near 1).

Since:
0.3
Author:
Arthur Zimek
• ### Nested Class Summary

Nested Classes
Modifier and Type Class Description
static class  SquaredPearsonCorrelationDistance.Par
Parameterization class.
• ### Field Summary

Fields
Modifier and Type Field Description
static SquaredPearsonCorrelationDistance STATIC
Static instance.
• ### Constructor Summary

Constructors
Constructor Description
SquaredPearsonCorrelationDistance()
Deprecated.
use static instance!
• ### Method Summary

All Methods
Modifier and Type Method Description
double distance​(NumberVector v1, NumberVector v2)
Computes the distance between two given vectors according to this distance function.
boolean equals​(java.lang.Object obj)
int hashCode()
boolean isSquared()
Squared distances, that would become metric after square root.
java.lang.String toString()
• ### Methods inherited from class elki.distance.AbstractNumberVectorDistance

dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, dimensionality, getInputTypeRestriction
• ### Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait
• ### Methods inherited from interface elki.distance.Distance

isMetric, isSymmetric
• ### Methods inherited from interface elki.distance.PrimitiveDistance

instantiate
• ### Field Detail

• #### STATIC

public static final SquaredPearsonCorrelationDistance STATIC
Static instance.
• ### Constructor Detail

• #### SquaredPearsonCorrelationDistance

@Deprecated
public SquaredPearsonCorrelationDistance()
Deprecated.
use static instance!
Constructor - use STATIC instead.
• ### Method Detail

• #### distance

public double distance​(NumberVector v1,
NumberVector v2)
Description copied from interface: NumberVectorDistance
Computes the distance between two given vectors according to this distance function.
Parameters:
v1 - first vector
v2 - second vector
Returns:
the distance between two given vectors according to this distance function
• #### isSquared

public boolean isSquared()
Description copied from interface: Distance
Squared distances, that would become metric after square root.

E.g. squared Euclidean.

Returns:
true when squared.
• #### toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object
• #### 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