WWFitter Class Reference

#include <WWFitter.h>

Inheritance diagram for WWFitter:

[legend]Collaboration diagram for WWFitter:

[legend]List of all members.

Public Member Functions
	WWFitter ()
virtual	~WWFitter ()
virtual double	fit ()
virtual int	getError () const
	Return error code.
virtual double	getProbability () const
virtual double	getChi2 () const
virtual int	getIterations () const
Protected Types
enum	{ NPARMAX = 50, NCONMAX = 20, NUNMMAX = 20 }
Protected Member Functions
virtual bool	initialize ()
virtual bool	updateFitObjects (double eta[])
Protected Attributes
int	npar
int	nmea
int	nunm
int	ncon
int	ierr
int	nit
double	fitprob
double	chi2

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Detailed Description

Description of the fit algorithm and interface:

The WWFitter object holds a set (fitobjects) of BaseFitObject objects, which represent the objects (particles, jets) whose fourvectors shall be fitted. It also holds a set (constraints) of BaseConstraint objects that represent the constraints (momentum or mass constraints).

WWFitter::initialize goes over the list of fit objects and determines the number of parameters (measured and unmeasured), and assigns global numbers to them.

WWFitter::fit first initializes the global parameter numbering using WWFitter::initialize.

Then it initializes vectors eta () and y () with the current parameter values.

Next it initializes the matrix dfeta that represents

Used methods in WWFitter::initialize:

• BaseFitObject::getNPar
• BaseFitObject::getMeasured
• BaseFitObject::setGlobalParNum

Used methods in WWFitter::updateFitObjects:

• BaseFitObject::getGlobalParNum
• BaseFitObject::setParam

Used methods in WWFitter::fit:

• BaseFitObject::getNPar
• BaseFitObject::getGlobalParNum
• BaseFitObject::getParam
• BaseFitObject::addToGlobCov
• BaseFitObject::operator<<
• BaseFitObject::setError
• BaseConstraint::getDerivatives
• BaseConstraint::getValue

Interaction between Constraints and Particles

The Fitter does not care how the constraints and BaseFitObject objects interact. The constraints are expressed in terms of four-vector components of the BaseFitObjects. A constraint object keeps a set of BaseFitObject objects, and, using the chain rule, calculates its derivatives w.r.t. the global parameters.

Definition at line 71 of file WWFitter.h.

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Member Enumeration Documentation

anonymous enum [protected]

Enumeration values: NPARMAX  NCONMAX  NUNMMAX  Definition at line 94 of file WWFitter.h.

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Constructor & Destructor Documentation

WWFitter::WWFitter (   )

Definition at line 44 of file WWFitter.C.

WWFitter::~WWFitter (   )  [virtual]

Definition at line 47 of file WWFitter.C.

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Member Function Documentation

double WWFitter::fit (   )  [virtual]

initialize dfeta ( = d F / d eta) Implements BaseFitter. Definition at line 50 of file WWFitter.C. References chi2, BaseFitter::constraints, dinv(), dsinv(), FDouble, FInteger, BaseFitter::fitobjects, fitprob, FReal, ierr, initialize(), ncon, NCONMAX, nit, nmea, npar, NPARMAX, nunm, NUNMMAX, prob(), and updateFitObjects(). Referenced by main().

double WWFitter::getChi2 (   )  const [virtual]

Implements BaseFitter. Definition at line 671 of file WWFitter.C. References chi2. Referenced by main().

int WWFitter::getError (   )  const [virtual]

Return error code. Error code meanings: 0: No error 1: out of iterations 2: crazy chi^2 3: minimum step size reached, chiK still increasing 4: (step size decreased) 5: (keep going) Implements BaseFitter. Definition at line 669 of file WWFitter.C. References ierr. Referenced by main().

int WWFitter::getIterations (   )  const [virtual]

Implements BaseFitter. Definition at line 672 of file WWFitter.C. References nit. Referenced by main().

double WWFitter::getProbability (   )  const [virtual]

Implements BaseFitter. Definition at line 670 of file WWFitter.C. References fitprob. Referenced by main().

bool WWFitter::initialize (   )  [protected, virtual]

Implements BaseFitter. Definition at line 604 of file WWFitter.C. References BaseFitter::constraints, BaseFitter::fitobjects, ncon, NCONMAX, nmea, npar, NPARMAX, nunm, and NUNMMAX. Referenced by fit().

bool WWFitter::updateFitObjects (  double  eta[]  )  [protected, virtual]

Definition at line 649 of file WWFitter.C. References BaseFitter::fitobjects. Referenced by fit().

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Member Data Documentation

double WWFitter::chi2 [protected]

Definition at line 104 of file WWFitter.h. Referenced by fit(), and getChi2().

double WWFitter::fitprob [protected]

Definition at line 103 of file WWFitter.h. Referenced by fit(), and getProbability().

int WWFitter::ierr [protected]

Definition at line 100 of file WWFitter.h. Referenced by fit(), and getError().

int WWFitter::ncon [protected]

Definition at line 99 of file WWFitter.h. Referenced by fit(), and initialize().

int WWFitter::nit [protected]

Definition at line 101 of file WWFitter.h. Referenced by fit(), and getIterations().

int WWFitter::nmea [protected]

Definition at line 97 of file WWFitter.h. Referenced by fit(), and initialize().

int WWFitter::npar [protected]

Definition at line 96 of file WWFitter.h. Referenced by fit(), and initialize().

int WWFitter::nunm [protected]

Definition at line 98 of file WWFitter.h. Referenced by fit(), and initialize().

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The documentation for this class was generated from the following files:

• WWFitter.h
• WWFitter.C

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