Rivet/Projections/ConstLossyFinalState.hh

0001 // -*- C++ -*-
0002 #ifndef RIVET_ConstLossyFinalState_HH
0003 #define RIVET_ConstLossyFinalState_HH
0004
0005 #include "Rivet/Tools/Logging.hh"
0006 #include "Rivet/Tools/Random.hh"
0007 #include "Rivet/Config/RivetCommon.hh"
0008 #include "Rivet/Particle.hh"
0009 #include "Rivet/Event.hh"
0010 #include "Rivet/Projection.hh"
0011 #include "Rivet/Projections/FinalState.hh"
0012 #include "Rivet/Projections/LossyFinalState.hh"
0013
0014 namespace Rivet {
0015
0016
0017   /// Functor used to implement constant random lossiness.
0018   class ConstRandomFilter {
0019   public:
0020
0021     ConstRandomFilter(double lossFraction)
0022       : _lossFraction(lossFraction)
0023     {
0024       assert(_lossFraction >= 0);
0025     }
0026
0027     // If operator() returns true, particle is deleted ("lost")
0028     bool operator()(const Particle&) {
0029       return rand01() < _lossFraction;
0030     }
0031
0032     CmpState compare(const ConstRandomFilter& other) const {
0033       return cmp(_lossFraction, other._lossFraction);
0034     }
0035
0036
0037   protected:
0038
0039     double _lossFraction;
0040
0041   };
0042
0043
0044
0045   /// @brief Randomly lose a constant fraction of particles.
0046   class ConstLossyFinalState : public LossyFinalState<ConstRandomFilter> {
0047   public:
0048
0049     /// @name Constructors
0050     /// @{
0051
0052     /// Constructor from a FinalState.
0053     ConstLossyFinalState(const FinalState& fsp, double lossfraction)
0054       : LossyFinalState<ConstRandomFilter>(fsp, ConstRandomFilter(lossfraction))
0055     {
0056       setName("ConstLossyFinalState");
0057     }
0058
0059     /// Stand-alone constructor. Initialises the base FinalState projection.
0060     ConstLossyFinalState(double lossfraction, const Cut& c=Cuts::open())
0061       : LossyFinalState<ConstRandomFilter>(ConstRandomFilter(lossfraction), c)
0062     {
0063       setName("ConstLossyFinalState");
0064     }
0065
0066     /// Clone on the heap.
0067     RIVET_DEFAULT_PROJ_CLONE(ConstLossyFinalState);
0068
0069     /// Import to avoid warnings about overload-hiding
0070     using Projection::operator =;
0071
0072     /// @}
0073
0074   };
0075
0076
0077 }
0078
0079 #endif