Package edu.cmu.tetrad.search.utils

Class KernelGaussian

java.lang.Object

edu.cmu.tetrad.search.utils.KernelGaussian

All Implemented Interfaces:

Kernel

public final class KernelGaussian
extends Object
implements Kernel

Soces the Gaussian kernel for a given bandwidth. Default bandwidth is set using the median distance heuristic.

Author:

Robert Tillman

Constructor Summary

Constructors

Constructor	Description
KernelGaussian(double sigma)	Creates a new Gaussian kernel with the given bandwidth
KernelGaussian(DataSet dataset, Node node)	Creates a new Gaussian kernel using the median distance between points to set the bandwidth

Method Summary

Modifier and Type	Method	Description
double	eval(double i, double j)	Evaluates the kernel at two given points
double	getBandwidth()	Gets kernel bandwidth
void	setDefaultBw(DataSet dataset, Node node)	Default setting of bandwidth based on median distance heuristic
void	setMedianBandwidth(DataSet dataset, Node node)	Sets the bandwidth of the kernel to median distance between two points in the given vector

Methods inherited from class java.lang.Object

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

Constructor Details

KernelGaussian

public KernelGaussian(double sigma)

Creates a new Gaussian kernel with the given bandwidth

Parameters:

sigma - the bandwidth

KernelGaussian

public KernelGaussian(DataSet dataset,
 Node node)

Creates a new Gaussian kernel using the median distance between points to set the bandwidth

Parameters:

dataset - dataet containing variable used to set bandwidth

node - variable used to set bandwidth

Method Details

getBandwidth

public double getBandwidth()

Description copied from interface: Kernel

Gets kernel bandwidth

Specified by:

getBandwidth in interface Kernel

Returns:

the bandwidth

eval

public double eval(double i,
 double j)

Evaluates the kernel at two given points

Specified by:

eval in interface Kernel

Parameters:

i - first point

j - second point

setDefaultBw

public void setDefaultBw(DataSet dataset,
 Node node)

Default setting of bandwidth based on median distance heuristic

Specified by:

setDefaultBw in interface Kernel

setMedianBandwidth

public void setMedianBandwidth(DataSet dataset,
 Node node)

Sets the bandwidth of the kernel to median distance between two points in the given vector

Parameters:

dataset - dataet containing variable used to set bandwidth

node - variable used to set bandwidth