CircleFitter (LCSim 3.1.7 API)

java.lang.Object
- org.lcsim.fit.circle.CircleFitter

```
public class CircleFitter
extends Object
```
A non-iterative circle fit based on the algorithm of V. Karimaki.

Version:

1.0

Author:

Norman A. Graf

Field Summary

Fields
Modifier and Type	Field and Description
`private double`	`_chicir`
`private double[]`	`_covrfd`
`private double`	`_dca`
`private double`	`_phi`
`private double`	`_rho`
`private double`	`_xpca`
`private double`	`_xref`
`private double`	`_xx0`
`private double`	`_ypca`
`private double`	`_yref`
`private double`	`_yy0`
`private double`	`S1`
`private double`	`S2`
`private double`	`S3`
`private double`	`S4`
`private double`	`S5`
`private double`	`S6`
`private double`	`S7`
`private double`	`S8`
`private double`	`S9`

Constructor Summary

Constructors
Constructor and Description

CircleFitter()
Default Constructor sets reference point to (0,0)

Constructors
Constructor and Description
`CircleFitter()` Default Constructor sets reference point to (0,0)

Method Summary

Methods
Modifier and Type	Method and Description
`private void`	`abatranspose(double[] A, double[] B)`
`boolean`	`fit(double[] XX, double[] YY, double[] WW, int NP)` Fit the data points
`CircleFit`	`getfit()` Get the results of the fit.
`(package private) void`	`propagate(double x, double y, double SINF, double COSF, double DIRTX, double DIRTY)`
`CircleFit`	`propagatefit(double x, double y)` Propagate the fit parameters to a new reference point
`void`	`setreferenceposition(double xref, double yref)` Set the reference point for the fit.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, 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
```

_chicir
```
private double _chicir
```

_xpca
```
private double _xpca
```

_ypca
```
private double _ypca
```

_covrfd
```
private double[] _covrfd
```

_xx0
```
private double _xx0
```

_yy0
```
private double _yy0
```

S1
```
private double S1
```

S2
```
private double S2
```

S3
```
private double S3
```

S4
```
private double S4
```

S5
```
private double S5
```

S6
```
private double S6
```

S7
```
private double S7
```

S8
```
private double S8
```

S9
```
private double S9
```

Constructor Detail
- CircleFitter
```
public CircleFitter()
```
  Default Constructor sets reference point to (0,0)

Method Detail
- setreferenceposition
```
public void setreferenceposition(double xref,
                        double yref)
```
  Set the reference point for the fit.
  
  Parameters:
  xref - x position of the reference point
  yref - y position of the reference point
- fit
```
public boolean fit(double[] XX,
          double[] YY,
          double[] WW,
          int NP)
```
  Fit the data points
  
  Parameters:
  XX - array of x positions
  YY - array of y positions
  WW - array of weights
  NP - number of points
  
  Returns:
  true if fit is successful
- getfit
```
public CircleFit getfit()
```
  Get the results of the fit.
  
  Returns:
  the results of the fit in a CircleFit object
- propagate
```
void propagate(double x,
             double y,
             double SINF,
             double COSF,
             double DIRTX,
             double DIRTY)
```
- propagatefit
```
public CircleFit propagatefit(double x,
                     double y)
```
  Propagate the fit parameters to a new reference point
  
  Parameters:
  x - x position of the new reference point
  y - y position of the new reference point
- abatranspose
```
private void abatranspose(double[] A,
                double[] B)
```

Class CircleFitter

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_xref

_yref

_rho

_phi

_dca

_chicir

_xpca

_ypca

_covrfd

_xx0

_yy0

S1

S2

S3

S4

S5

S6

S7

S8

S9

Constructor Detail

CircleFitter

Method Detail

setreferenceposition

fit

getfit

propagate

propagatefit

abatranspose