include/ninja/rambo.hh

0001 #ifndef NINJA_RAMBO_HH
0002 #define NINJA_RAMBO_HH
0003
0004 #include <ninja/types.hh>
0005 #include <ninja/momentum.hh>
0006
0007 namespace ninja {
0008
0009   namespace detail {
0010     class RandomGenerator;
0011     RandomGenerator * newRandomGenerator();
0012     void deleteRandomGenerator(RandomGenerator * gen);
0013   }
0014
0015
0016   class Rambo {
0017
0018   public:
0019     enum {SUCCESS, NEWTON_METHOD_FAILED=1};
0020
0021   public:
0022
0023     Rambo()
0024       : m_(0), rnd_(detail::newRandomGenerator()), s_(0), n_(0), flag_(0) {}
0025
0026     Rambo(Real energy, unsigned n, const Real masses[] = 0)
0027       : m_(masses), rnd_(detail::newRandomGenerator()),
0028         s_(energy), n_(n), flag_(SUCCESS)
0029     {}
0030
0031     ~Rambo()
0032     {
0033       detail::deleteRandomGenerator(rnd_);
0034     }
0035
0036     Rambo & setNParticles(unsigned n)
0037     {
0038       n_ = n;
0039       return *this;
0040     }
0041
0042     Rambo & setEnergy(Real energy)
0043     {
0044       s_ = energy;
0045       return *this;
0046     }
0047
0048
0049     Rambo & setMasses(const Real * masses)
0050     {
0051       m_ = masses;
0052       return *this;
0053     }
0054
0055     Rambo & setSeed(int seed);
0056
0057     int getMomenta(RealMomentum vecs[], Real * weight = 0);
0058
0059   private:
0060
0061     void getIncomingMomenta_(RealMomentum vecs[]);
0062     Real rambo0_(RealMomentum u[], RealMomentum vecs[]);
0063     Real newton_(RealMomentum vecs[]);
0064
0065   private:
0066     const Real * m_;
0067     detail::RandomGenerator * rnd_;
0068     Real s_;
0069     int n_, flag_;
0070   };
0071
0072 }
0073
0074 #endif // RAMBO_HH