NormalizingKernel (biojava-legacy 1.9.5 API)

java.lang.Object
- org.biojava.stats.svm.NestedKernel
- - org.biojava.stats.svm.NormalizingKernel

All Implemented Interfaces:

Serializable, SVMKernel
```
public class NormalizingKernel
extends NestedKernel
```
Performs a normalization on the results of a nested kernel.
This is equivalent to making the locations in feature space of the nested kernel unit vectors lying on a unit sphere. The dot product in feature space then becomes just cos theta rather than ||a|| * ||b|| * cos theta as both lengths are 1. The length of a in the feature space of kernel k is sqrt( k(a, a) ), so that the normalizing kernel ends up calculating k(a, b) / sqrt( k(a, a) * k(b, b) ).
As the values of k(x, x) are required repeatedly, it may be worth making the nested kernel a DiagonalCachingKernel.

Author:

Thomas Down, Matthew Pocock

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

NormalizingKernel()

NormalizingKernel(SVMKernel k)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`evaluate(Object a, Object b)`	Return the dot product of two vectors in an arbitrary feature space.
`String`	`toString()`

Methods inherited from class org.biojava.stats.svm.NestedKernel
getNestedKernel, setNestedKernel

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - NormalizingKernel
```
public NormalizingKernel()
```
  - NormalizingKernel
```
public NormalizingKernel(SVMKernel k)
```
- Method Detail
  - evaluate
```
public double evaluate(Object a,
                       Object b)
```
    Description copied from interface: SVMKernel
    
    Return the dot product of two vectors in an arbitrary feature space. In this implementation, the `vectors' can actually be arbitrary objects.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object