Abstract base class for constraints of kinematic fits. More...

#include <TrackConstraint.h>

Inheritance diagram for TrackConstraint:

Collaboration diagram for TrackConstraint:

[legend]

Public Member Functions
	TrackConstraint ()
	Creates an empty TrackConstraint object.

virtual	~TrackConstraint ()
	Virtual destructor.

virtual void	setFOList (std::vector< TrackFitObject * > *fitobjects_)
	Adds several TrackFitObject objects to the list. More...

virtual void	addToFOList (TrackFitObject &fitobject, int flag=1)
	Adds one TrackFitObject objects to the list.

virtual double	getValue () const =0
	Returns the value of the constraint.

virtual void	getDerivatives (int idim, double der[]) const =0
	Get first order derivatives. More...

virtual void	add1stDerivativesToMatrix (double *M, int idim) const
	Adds first order derivatives to global covariance matrix M. More...

virtual void	add2ndDerivativesToMatrix (double *M, int idim, double lambda) const
	Adds second order derivatives to global covariance matrix M. More...

virtual void	addToGlobalChi2DerVector (double *y, int idim, double lambda) const
	Add lambda times derivatives of chi squared to global derivative matrix. More...

virtual int	getGlobalNum () const
	Accesses position of constraint in global constraint list.

virtual void	setGlobalNum (int iglobal)
	Sets position of constraint in global constraint list.

virtual void	invalidateCache () const
	Invalidates any cached values for the next event.

virtual double	getError () const
	Returns the error on the value of the constraint.

virtual const char *	getName () const
	Returns the name of the constraint.

void	setName (const char *name_)
	Set object's name.

virtual std::ostream &	print (std::ostream &os) const
	print object to ostream More...

Protected Types
typedef std::vector< TrackFitObject * >	FitObjectContainer
	Vector of pointers to TrackFitObjects.

typedef FitObjectContainer::iterator	FitObjectIterator
	Iterator through vector of pointers to TrackFitObjects.

typedef FitObjectContainer::const_iterator	ConstFitObjectIterator
	Constant iterator through vector of pointers to TrackFitObjects.

Protected Attributes
FitObjectContainer	fitobjects
	The FitObjectContainer.

std::vector< double >	derivatives
	The derivatives.

std::vector< int >	flags
	The flags can be used to divide the FitObjectContainer into several subsets used for example to implement an equal mass constraint (see MassConstraint).

std::vector< double >	sign

int	globalNum
	Position of constraint in global constraint list.

char *	name

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &os, const BaseConstraint &bc)
	Prints out a BaseConstraint, using its print method. More...

Detailed Description

Abstract base class for constraints of kinematic fits.

This class defines the minimal functionality any constraint class must provide. First of all a constraint should know on with particles (or FitObject) it is applied. Where as for example a constraint on the total transvese momentum takes into account all particles in the event, an invariant mass constraint usually applies only to a subset of particles.

The particle list is implemented as a vector containing pointers to objects derived from TrackFitObject and can be either set a whole (setFOList) or enlarged by adding a single TrackFitObject (addToFOList).

From the four–momenta of all concerned fit objects the constraint has to be able to calculate its current value (getValue). Constraints should be formulated such that a value of zero corresponds to a perfectly fulfilled constraint.

In order to find a solution to the constrained minimisation problem, fit algorithms usually need the first order derivatives of the constraint with respect to the fit parameters. Since many constraints can be most easily expressed in terms of E, px, py, pz, the constraints supply their derivatives w.r.t. these parameters. If a FitObject uses a different parametrisation, it is its own task to provide the additional derivatives of E, px, py, pz w.r.t. the parameters of the FitObject. Thus it is easily possible to use FitObjects with different kinds of parametrisations under the same constraint. Some fit algorithms also need the second derivatives of the constraint, i.e. the NewtonFitter.

First and second order derivatives of each constraint can be added directly to the global covariance matrix containing the derivatives of all constraints w.r.t. to all parameters (add1stDerivativesToMatrix, add2ndDerivativesToMatrix). This requires the constraint to know its position in the overall list of constraints (globalNum).

Author: Benno List, Jenny List

Date: 2008/01/30 09:14:54

Author: blist

Definition at line 73 of file TrackConstraint.h.

Member Function Documentation

◆ add1stDerivativesToMatrix()

virtual void add1stDerivativesToMatrix	(	double *	M,
		int	idim
	)		const

inlinevirtual

Adds first order derivatives to global covariance matrix M.

Parameters

M	Covariance matrix, at least idim x idim
idim	First dimension of the array

Definition at line 105 of file TrackConstraint.h.

108 {assert(false);}

◆ add2ndDerivativesToMatrix()

virtual void add2ndDerivativesToMatrix	(	double *	M,
		int	idim,
		double	lambda
	)		const

inlinevirtual

Adds second order derivatives to global covariance matrix M.

Parameters

M	Global covariance matrix, dimension at least idim x idim
idim	First dimension of array der
lambda	Lagrange multiplier for this constraint

Definition at line 110 of file TrackConstraint.h.

◆ addToGlobalChi2DerVector()

virtual void addToGlobalChi2DerVector	(	double *	y,
		int	idim,
		double	lambda
	)		const

inlinevirtual

Add lambda times derivatives of chi squared to global derivative matrix.

Parameters

y	Vector of chi2 derivatives
idim	Vector size

Definition at line 117 of file TrackConstraint.h.

◆ getDerivatives()

virtual void getDerivatives	(	int	idim,
		double	der[]
	)		const

pure virtual

Get first order derivatives.

Call this with a predefined array "der" with the necessary number of entries!

Implements BaseConstraint.

◆ print()

std::ostream & print ( std::ostream & os ) const

virtualinherited

print object to ostream

Parameters

os	The output stream

Definition at line 76 of file BaseConstraint.cc.

◆ setFOList()

virtual void setFOList ( std::vector< TrackFitObject * > * fitobjects_ )

inlinevirtual

Adds several TrackFitObject objects to the list.

Parameters

fitobjects_ A list of BaseFitObject objects

Definition at line 81 of file TrackConstraint.h.

Friends And Related Function Documentation

◆ operator<<()

std::ostream & operator<<	(	std::ostream &	os,
		const BaseConstraint &	bc
	)

Parameters

os	The output stream
bc	The object to print

Definition at line 114 of file BaseConstraint.h.

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

analysis/OrcaKinFit/include/TrackConstraint.h

Public Member Functions

Protected Types

Protected Attributes

Related Functions

Detailed Description

Member Function Documentation

◆ add1stDerivativesToMatrix()

◆ add2ndDerivativesToMatrix()

◆ addToGlobalChi2DerVector()

◆ getDerivatives()

◆ print()

◆ setFOList()

Friends And Related Function Documentation

◆ operator<<()