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)
Re-creates 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

Re-creates 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 elvaluation 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 ScoringFunctions 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

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 set 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