KinematicFitPrimitives/interface/MultiTrackKinematicConstraint.h

0001 #ifndef MultiTrackKinematicConstraint_H
0002 #define MultiTrackKinematicConstraint_H
0003
0004 #include "RecoVertex/KinematicFitPrimitives/interface/RefCountedKinematicParticle.h"
0005 #include "RecoVertex/KinematicFitPrimitives/interface/RefCountedKinematicVertex.h"
0006 #include "DataFormats/CLHEP/interface/AlgebraicObjects.h"
0007
0008 /**
0009  * Pure abstract class implementing constraint application
0010  * on multiple tracks (back to back, collinearity etc.)
0011  * To be used by KinematicConstraindeVertexFitter only
0012  * Class caches the information about calculation of
0013  * of constraint equation derivatives and values at given
0014  * linearization point. Point should be of 7*n+3 dimensions
0015  * Where n - number of particles. 7 - parametrization for
0016  * particles is (x,y,z,p_x,p_y,p_z,m), for vertex (x_v,y_v,z_v)
0017  * Fitter usually takes current parameters as the first step point
0018  * and the change it to the result of the first iteration.
0019  *
0020  * Kirill Prokofiev, October 2003
0021  */
0022
0023 class MultiTrackKinematicConstraint {
0024 public:
0025   /**
0026  *  Default constructor and destructor
0027  */
0028
0029   MultiTrackKinematicConstraint() {}
0030
0031   virtual ~MultiTrackKinematicConstraint() {}
0032
0033   /**
0034  * Methods making vector of values
0035  * and derivative matrices with
0036  * respect to vertex position and
0037  * particle parameters.
0038  * Input paramters are put into one vector:
0039  * (Vertex position, particle_parameters_1,..., particle_parameters_n)
0040  */
0041   virtual AlgebraicVector value(const std::vector<KinematicState>&, const GlobalPoint&) const = 0;
0042
0043   virtual AlgebraicMatrix parametersDerivative(const std::vector<KinematicState>&, const GlobalPoint&) const = 0;
0044
0045   virtual AlgebraicMatrix positionDerivative(const std::vector<KinematicState>&, const GlobalPoint&) const = 0;
0046
0047   virtual int numberOfEquations() const = 0;
0048
0049   virtual MultiTrackKinematicConstraint* clone() const = 0;
0050 };
0051
0052 #endif