dwvisser.analysis
Class GaussianFit

java.lang.Object
  |
  +--dwvisser.analysis.NonLinearFit
        |
        +--dwvisser.analysis.GaussianFit

public class GaussianFit

extends NonLinearFit

This abstract class uses NonLinearFit to fit a single gaussian peak with a background.. The background is a polynomial up to a quadradic term if desired. (Channel - Centroid) is the term the polynomial is expanded in.

Version:

0.5, 20 February 2001

Author:

Dale Visser

See Also:

NonLinearFit

Field Summary

static java.lang.String	AREA name of Parameter--area of peak
static java.lang.String	CENTROID name of Parameter--centroid of peak
static java.lang.String	WIDTH name of Parameter--width of peak

Fields inherited from class dwvisser.analysis.NonLinearFit

chisq, counts, errors, lm, maxCH, minCH

Constructor Summary

GaussianFit(double[] spectrum, double[] errors, int begin, int end, Multiplet m)
Class constructor.

Method Summary

double	derivative(double x, java.lang.String parName) Evaluates derivative with respect to parameterName at x.
void	estimate() If so requested, estimates A, Area, and Width.
Multiplet	getFitResult()
double	valueAt(double x) Calculates the gaussian with background at a given x.

Methods inherited from class dwvisser.analysis.NonLinearFit

addParameter, calculate, doFit, getParameter, p, setParameter

Methods inherited from class java.lang.Object

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

Field Detail

CENTROID

public static final java.lang.String CENTROID

name of Parameter--centroid of peak

See Also:

Constant Field Values

WIDTH

public static final java.lang.String WIDTH

name of Parameter--width of peak

See Also:

Constant Field Values

AREA

public static final java.lang.String AREA

name of Parameter--area of peak

See Also:

Constant Field Values

Constructor Detail

GaussianFit

public GaussianFit(double[] spectrum,
                   double[] errors,
                   int begin,
                   int end,
                   Multiplet m)
            throws FitException

Class constructor.

Method Detail

estimate

public void estimate()
              throws FitException

If so requested, estimates A, Area, and Width.

Specified by:

estimate in class NonLinearFit

Throws:

FitException - thrown if unrecoverable error occurs during estimation

valueAt

public double valueAt(double x)

Calculates the gaussian with background at a given x.

Specified by:

valueAt in class NonLinearFit

Parameters:

x - value to calculate at

Returns:

value of function at x

derivative

public double derivative(double x,
                         java.lang.String parName)

Evaluates derivative with respect to parameterName at x.

Specified by:

derivative in class NonLinearFit

Parameters:

x - value to evalueate at

parName - the name of the parameter to differentiate with respect to

Returns:

df(x)/d(parameterName) at x

getFitResult

public Multiplet getFitResult()