CLHEP/GenericFunctions/PhaseSpace.hh

0001 // This is a class the creates an N-Dimensional Phase Space     //
0002
0003 // It is for use in computing the time development of classical //
0004 // Hamiltonian Systems.                                         //
0005
0006 // Joe Boudreau October 2011                                    //
0007
0008 //--------------------------------------------------------------//
0009
0010 #ifndef _PHASE_SPACE_
0011 #define _PHASE_SPACE_
0012 #include "CLHEP/GenericFunctions/Variable.hh"
0013 #include <vector>
0014
0015 namespace Classical {
0016
0017   class PhaseSpace {
0018
0019
0020   public:
0021
0022     // A component is like a vector: of coordinates or momenta:
0023     class Component;
0024
0025     // constructor
0026     PhaseSpace(unsigned int NDIM);
0027
0028     // Destructor
0029     ~PhaseSpace();
0030
0031     // Get the dimensionality:
0032     unsigned int dim() const;
0033
0034     // Get the coordinates:
0035     const Component & coordinates() const;
0036
0037     // Get the momenta:
0038     const Component & momenta()     const;
0039
0040     // Set starting values for the coordinates or momenta:
0041     void   start (const Genfun::Variable & variable, double value);
0042
0043     // Get starting values for the coordinates or momenta:
0044     double startValue(const Genfun::Variable & component) const ;
0045
0046
0047     // Each component has N-dimensions:
0048     class Component {
0049
0050     public:
0051
0052       // Access to the ith element;
0053       Genfun::Variable operator [] (unsigned int i) const;
0054
0055     private:
0056
0057       // Constructor:
0058       Component(unsigned int NDIM, bool isMomentum);
0059
0060       // Destructor:
0061       ~Component();
0062
0063       // Illegal operations:
0064       Component (const Component &);
0065       Component & operator=(const Component &);
0066
0067       // Internal clockwork;
0068       class Clockwork;
0069       Clockwork *c;
0070       friend class PhaseSpace;
0071
0072     };
0073
0074   private:
0075
0076     Component _coordinates;
0077     Component _momenta;
0078     std::vector<double> _q0;
0079     std::vector<double> _p0;
0080     unsigned int DIM;
0081   };
0082
0083 }
0084 #endif
0085