jasext.hist.function

Class LandauFunction

java.lang.Object

java.util.Observable

jas2.hist.Basic1DFunction

jas2.hist.Fittable1DFunction

jasext.hist.function.LandauFunction

All Implemented Interfaces:

DataSource, ExtendedStatistics, FunctionData, HasHandles, HasStatistics, Statistics, java.io.Serializable

public class LandauFunction
extends Fittable1DFunction
implements HasHandles

The function represents the Landau distribution. This class represents a Landau distribution, as approximated by the Moyal formula \[ Moyal(\lambda) = \frac{\exp{-0.5(\lambda+\exp{-\lambda})}}{\sqrt{2\pi}} \] See J.E. Moyal, Theory of ionization fluctuations, Phil. Mag. 46 (1955) 263. Note that this analytical approximation is too low in the tail. In order to allow for a fit, we define \[ \lambda = \frac{x - m}{s} \] with x the dataset variable.

See Also:

Serialized Form

Field Summary

Fields inherited from interface jas2.hist.DataSource

DATE, DELTATIME, DOUBLE, INTEGER, STRING

Constructor Summary

Constructors

Constructor and Description
LandauFunction(double amplitude, double mean, double sigma)
LandauFunction(double xmin, double xmax, double ymin, double ymax)

Method Summary

Modifier and Type	Method and Description
Handle[]	getHandles(double xLow, double xHigh, double yLow, double yHigh)
java.lang.String[]	getParameterNames()
double[]	getParameterValues()
Statistics	getStatistics()
java.lang.String	getTitle() Return the caption to be used in the legend for this data.
void	setFit(Fitter fit, double[] value)
void	setParameter(int index, double value)
double	valueAt(double x)
double	valueAt(double x, double[] a)

Methods inherited from class jas2.hist.Fittable1DFunction

clearFit, clearFitParams, getDerivatives, getExtendedStatistic, getFit, getIncludeParametersInFit, getStatistic, getStatisticNames, setIncludeParameterInFit

Methods inherited from class jas2.hist.Basic1DFunction

setBatch, setChanged, setChanged

Methods inherited from class java.util.Observable

addObserver, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers

Methods inherited from class java.lang.Object

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

Constructor Detail

LandauFunction

public LandauFunction(double amplitude,
                      double mean,
                      double sigma)

LandauFunction

public LandauFunction(double xmin,
                      double xmax,
                      double ymin,
                      double ymax)

Method Detail

valueAt

public double valueAt(double x)

Specified by:

valueAt in interface FunctionData

valueAt

public double valueAt(double x,
                      double[] a)

Specified by:

valueAt in class Fittable1DFunction

getParameterNames

public java.lang.String[] getParameterNames()

Specified by:

getParameterNames in interface FunctionData

getParameterValues

public double[] getParameterValues()

Specified by:

getParameterValues in interface FunctionData

setParameter

public void setParameter(int index,
                         double value)

Specified by:

setParameter in interface FunctionData

setFit

public void setFit(Fitter fit,
                   double[] value)

Specified by:

setFit in class Fittable1DFunction

getTitle

public java.lang.String getTitle()

Description copied from interface: DataSource

Return the caption to be used in the legend for this data.

Specified by:

getTitle in interface DataSource

getStatistics

public Statistics getStatistics()

Specified by:

getStatistics in interface HasStatistics

Overrides:

getStatistics in class Basic1DFunction

getHandles

public Handle[] getHandles(double xLow,
                           double xHigh,
                           double yLow,
                           double yHigh)

Specified by:

getHandles in interface HasHandles