org.lcsim.fit.circle

Class CircleFit

java.lang.Object

org.lcsim.fit.circle.CircleFit

public class CircleFit
extends Object

Encapsulates the behavior of a circle fit to data points. Used in high-energy physics for a fit to hits left by charged particles originating near (0,0) in a constant magnetic field.

Version:

1.0

Author:

Norman A. Graf

Field Summary

Fields

Modifier and Type	Field and Description
private double	_chisq
private double[]	_covrfd
private double	_dca
private double	_phi
private double	_rho
private double	_xref
private double	_yref

Constructor Summary

Constructors

Constructor and Description
CircleFit(double x, double y, double rho, double phi, double dca, double chi2, double[] cov)

Method Summary

Methods

Modifier and Type	Method and Description
double	chisq() The chi-squared for the fit.
double[]	cov() The covariance matrix of fit
double	curvature() The curvature of the fit.
double	dca() The distance of closest approach to the reference point.
double	phi() The phi angle at the point of reference.
String	toString() String representation of this object
double	xref() The x position of the reference point
double	yref() The y position of the reference point.

Methods inherited from class java.lang.Object

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

Field Detail

_xref

private double _xref

_yref

private double _yref

_rho

private double _rho

_phi

private double _phi

_dca

private double _dca

_chisq

private double _chisq

_covrfd

private double[] _covrfd

Constructor Detail

CircleFit

public CircleFit(double x,
         double y,
         double rho,
         double phi,
         double dca,
         double chi2,
         double[] cov)

Method Detail

phi

public double phi()

The phi angle at the point of reference.

Returns:

phi

curvature

public double curvature()

The curvature of the fit.

Returns:

the fit curvature.

xref

public double xref()

The x position of the reference point

Returns:

x reference point.

yref

public double yref()

The y position of the reference point.

Returns:

y reference point.

dca

public double dca()

The distance of closest approach to the reference point.

Returns:

distance of closest approach to (xref, yref)

chisq

public double chisq()

The chi-squared for the fit.

Returns:

chi-squared for the circle fit.

cov

public double[] cov()

The covariance matrix of fit

Returns:

covariance matrix of fit

toString

public String toString()

String representation of this object

Overrides:

toString in class Object

Returns:

string representation of this object.