com.imsl.datamining.supportvectormachine

Class RadialBasisKernel

java.lang.Object

com.imsl.datamining.supportvectormachine.Kernel

com.imsl.datamining.supportvectormachine.RadialBasisKernel

All Implemented Interfaces:

Cloneable

public class RadialBasisKernel
extends Kernel

Specifies the radial basis kernel for support vector machines.

The kernel function at two data nodes, \(x_i\) and \(x_j\), is given by \(K(x_i , x_j) = \exp (-\gamma { \parallel x_i-x_j \parallel }^2)\), where \(\gamma \gt 0 \) is a configurable parameter.

Constructor Summary

Constructors

Constructor and Description
RadialBasisKernel() Constructs a radial basis kernel with a \(\gamma\) value of 1.0.
RadialBasisKernel(double gamma) Constructs a radial basis kernel.
RadialBasisKernel(RadialBasisKernel radialBasisKernel) Constructs a copy of the input RadialBasisKernel kernel.

Method Summary

Modifier and Type	Method and Description
RadialBasisKernel	clone() Clones a RadialBasisKernel kernel.
double	kernelFunction(DataNode[][] x, int i, int j) Calculates the kernel function between two DataNodes.
double	kernelFunction(DataNode[] x, DataNode[] y) Calculates the kernel function between two DataNodes.
void	setParameters(double... kParams) Sets the parameters for the radial basis kernel.

Methods inherited from class com.imsl.datamining.supportvectormachine.Kernel

dot, getParameters

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RadialBasisKernel

public RadialBasisKernel()

Constructs a radial basis kernel with a \(\gamma\) value of 1.0.

RadialBasisKernel

public RadialBasisKernel(double gamma)

Constructs a radial basis kernel.

Parameters:

gamma - a double, the radial basis kernel free parameter

RadialBasisKernel

public RadialBasisKernel(RadialBasisKernel radialBasisKernel)

Constructs a copy of the input RadialBasisKernel kernel.

Parameters:

radialBasisKernel - a RadialBasisKernel kernel

Method Detail

clone

public RadialBasisKernel clone()

Clones a RadialBasisKernel kernel.

Specified by:

clone in class Kernel

Returns:

a clone of the RadialBasisKernel kernel

setParameters

public void setParameters(double... kParams)

Sets the parameters for the radial basis kernel.

Overrides:

setParameters in class Kernel

Parameters:

kParams - a double array of length 1 containing the parameter value: kParams[0]=\(\gamma\)

Default: kParams[0]=\(\gamma\)=1.0

kernelFunction

public double kernelFunction(DataNode[] x,
                             DataNode[] y)

Calculates the kernel function between two DataNodes.

Specified by:

kernelFunction in class Kernel

Parameters:

x - a DataNode array

y - a DataNode array

Returns:

a double, the kernel function evaluated at x and y

kernelFunction

public double kernelFunction(DataNode[][] x,
                             int i,
                             int j)

Calculates the kernel function between two DataNodes.

Specified by:

kernelFunction in class Kernel

Parameters:

x - a DataNode matrix

i - an int, index to the first DataNode, x[i]

j - an int, index to the second DataNode, x[j]

Returns:

a double, the kernel function evaluated at x[i] and x[j]