SigmoidKernel (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- elki.similarity.AbstractVectorSimilarity
- - elki.similarity.kernel.SigmoidKernel

All Implemented Interfaces:

PrimitiveSimilarity<NumberVector>, Similarity<NumberVector>
```
@Alias("sigmoid")
public class SigmoidKernel
extends AbstractVectorSimilarity
```
Sigmoid kernel function (aka: hyperbolic tangent kernel, multilayer perceptron MLP kernel).

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class SigmoidKernel.Par
Parameterization class.

Field Summary

Fields
Modifier and Type Field Description

private double c
Scaling factor c, bias theta

private double theta
Scaling factor c, bias theta

Constructor Summary

Constructors
Constructor Description

SigmoidKernel(double c, double theta)
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`similarity(NumberVector o1, NumberVector o2)`	Computes the similarity between two given DatabaseObjects according to this similarity function.

Methods inherited from class elki.similarity.AbstractVectorSimilarity
getInputTypeRestriction

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

Methods inherited from interface elki.similarity.PrimitiveSimilarity
instantiate

Methods inherited from interface elki.similarity.Similarity
isSymmetric

- Field Detail
  - c
```
private final double c
```
    Scaling factor c, bias theta
  - theta
```
private final double theta
```
    Scaling factor c, bias theta
- Constructor Detail
  - SigmoidKernel
```
public SigmoidKernel(double c,
                     double theta)
```
    Constructor.
    
    Parameters:
    
    c - Scaling factor c.
    
    theta - Bias parameter theta.
- Method Detail
  - similarity
```
public double similarity(NumberVector o1,
                         NumberVector o2)
```
    Description copied from interface: PrimitiveSimilarity
    
    Computes the similarity between two given DatabaseObjects according to this similarity function.
    
    Parameters:
    
    o1 - first DatabaseObject
    
    o2 - second DatabaseObject
    
    Returns:
    
    the similarity between two given DatabaseObjects according to this similarity function