de.jstacs.classifier.scoringFunctionBased.logPrior
Class SimpleGaussianSumLogPrior

java.lang.Object
  de.jstacs.algorithms.optimization.DifferentiableFunction
      de.jstacs.classifier.scoringFunctionBased.logPrior.LogPrior
          de.jstacs.classifier.scoringFunctionBased.logPrior.SimpleGaussianSumLogPrior

All Implemented Interfaces:

Function, Storable

public class SimpleGaussianSumLogPrior
extends LogPrior

This class implements a prior that is a product of Gaussian distributions with mean 0 and equal variance for each parameter.

Author:

Jens Keilwagen

Field Summary

Fields inherited from class de.jstacs.classifier.scoringFunctionBased.logPrior.LogPrior

UNKNOWN

Constructor Summary

SimpleGaussianSumLogPrior(double sigma)
Creates a new SimpleGaussianSumLogPrior with mean 0 and variance sigma for all parameters, including the class parameters.

SimpleGaussianSumLogPrior(StringBuffer xml)
Recreates a SimpleGaussianSumLogPrior from its XML representation as returned by toXML().

Method Summary

void	addGradientFor(double[] params, double[] grad) Adds the gradient of the log-prior using the current parameters to a given vector.
double	evaluateFunction(double[] params) Evaluates the function at a certain vector (in mathematical sense) x.
int	getDimensionOfScope() Returns the dimension of the scope of the function.
String	getInstanceName() Returns a short instance name.
SimpleGaussianSumLogPrior	getNewInstance() This method returns an empty new instance of the current prior.
StringBuffer	toXML() Encodes the prior as an XML representation.

Methods inherited from class de.jstacs.classifier.scoringFunctionBased.logPrior.LogPrior

evaluateGradientOfFunction, set

Methods inherited from class de.jstacs.algorithms.optimization.DifferentiableFunction

findOneDimensionalMin

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleGaussianSumLogPrior

public SimpleGaussianSumLogPrior(double sigma)

Creates a new SimpleGaussianSumLogPrior with mean 0 and variance sigma for all parameters, including the class parameters.

Parameters:

sigma - the variance

SimpleGaussianSumLogPrior

public SimpleGaussianSumLogPrior(StringBuffer xml)
                          throws NonParsableException

Recreates a SimpleGaussianSumLogPrior from its XML representation as returned by toXML().

Parameters:

xml - the XML representation

Throws:

NonParsableException - is thrown if the XML code could not be parsed

Method Detail

addGradientFor

public void addGradientFor(double[] params,
                           double[] grad)

Description copied from class: LogPrior

Adds the gradient of the log-prior using the current parameters to a given vector.

Specified by:

addGradientFor in class LogPrior

Parameters:

params - the parameters

grad - the vector

evaluateFunction

public double evaluateFunction(double[] params)

Description copied from interface: Function

Evaluates the function at a certain vector (in mathematical sense) x.

Parameters:

params - the current vector

Returns:

the evaluation of the function

getDimensionOfScope

public int getDimensionOfScope()

Description copied from interface: Function

Returns the dimension of the scope of the function.

Returns:

dimension of the scope; n, with f: R^n -> R

getNewInstance

public SimpleGaussianSumLogPrior getNewInstance()
                                         throws CloneNotSupportedException

Description copied from class: LogPrior

This method returns an empty new instance of the current prior. The method works similar to clone, but does not clone ScoringFunction s that may be inside the instance. The ScoringFunctions must be set by an invocation of the method LogPrior.set(boolean, ScoringFunction...).

Specified by:

getNewInstance in class LogPrior

Returns:

a new empty instance of the prior

Throws:

CloneNotSupportedException - if something went wrong while cloning

See Also:

LogPrior.set(boolean, ScoringFunction...)

toXML

public StringBuffer toXML()

Description copied from class: LogPrior

Encodes the prior as an XML representation. It does not encode all information, since the method LogPrior.set(boolean, ScoringFunction...) has to be invoked after decoding.

Specified by:

toXML in interface Storable

Specified by:

toXML in class LogPrior

Returns:

the XML representation;

getInstanceName

public String getInstanceName()

Description copied from class: LogPrior

Returns a short instance name.

Specified by:

getInstanceName in class LogPrior

Returns:

a short instance name