STARLIGHT code and interface

[u/mrichter/AliRoot.git] / STARLIGHT / starlight / include / lorentzvector.h

diff --git a/STARLIGHT/starlight/include/lorentzvector.h b/STARLIGHT/starlight/include/lorentzvector.h
new file mode 100644 (file)
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+++ b/STARLIGHT/starlight/include/lorentzvector.h
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+///////////////////////////////////////////////////////////////////////////
+//
+//    Copyright 2010
+//
+//    This file is part of starlight.
+//
+//    starlight is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    starlight is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+//    GNU General Public License for more details.
+//
+//    You should have received a copy of the GNU General Public License
+//    along with starlight. If not, see <http://www.gnu.org/licenses/>.
+//
+///////////////////////////////////////////////////////////////////////////
+//
+// File and Version Information:
+// $Rev:: 28                          $: revision of last commit
+// $Author:: bgrube                   $: author of last commit
+// $Date:: 2010-12-10 19:30:01 +0100 #$: date of last commit
+//
+// Description:
+//
+//
+//
+///////////////////////////////////////////////////////////////////////////
+
+
+#ifndef LORENTZVECTOR_H
+#define LORENTZVECTOR_H
+
+
+#include "vector3.h"
+#include <vector>
+
+
+class lorentzVector
+{
+   public:
+      
+      lorentzVector();
+      virtual ~lorentzVector();
+      
+      lorentzVector(double x, double y, double z, double t);
+      //lorentzVector(double px, double py, double pz, double e);
+      
+      void SetXYZT(double x, double y, double z, double t);
+           void SetPxPyPzE(double px, double py, double pz, double e) { SetXYZT(px, py, pz, e); };
+      
+      double GetPx() const { return fSpaceVec.GetVector()[0]; }
+      double GetPy() const { return fSpaceVec.GetVector()[1]; }
+      double GetPz() const { return fSpaceVec.GetVector()[2]; }
+      double GetE() const { return fTime; }
+
+           lorentzVector& operator +=(const lorentzVector& vec)
+           {
+                   fSpaceVec += vec.fSpaceVec;
+                   fTime     += vec.fTime;
+                   return *this;
+           }
+           lorentzVector& operator -=(const lorentzVector& vec)
+           {
+                   fSpaceVec -= vec.fSpaceVec;
+                   fTime     -= vec.fTime;
+                   return *this;
+           }
+
+           double M2() const { return fTime * fTime - fSpaceVec.Mag2(); }
+      double M () const
+           {
+             const double mag2 = M2();
+             return (mag2 < 0) ? -sqrt(-mag2) : sqrt(mag2);
+      }
+
+           vector3 BoostVector() const
+           { return vector3(fSpaceVec.X() / fTime, fSpaceVec.Y() / fTime, fSpaceVec.Z() / fTime); }
+           void Boost(const vector3& beta)
+           {
+                   const double beta2        = beta.Mag2();
+                   const double gamma        = 1 / sqrt(1 - beta2);
+                   const double betaTimesMom = beta.X() * fSpaceVec.X() + beta.Y() * fSpaceVec.Y() + beta.Z() * fSpaceVec.Z();
+                   const double gamma2       = (beta2 > 0) ? (gamma - 1) / beta2 : 0;
+                   SetXYZT(fSpaceVec.X() + gamma2 * betaTimesMom * beta.X() + gamma * beta.X() * fTime,
+                           fSpaceVec.Y() + gamma2 * betaTimesMom * beta.Y() + gamma * beta.Y() * fTime,
+                           fSpaceVec.Z() + gamma2 * betaTimesMom * beta.Z() + gamma * beta.Z() * fTime,
+                           gamma * (fTime + betaTimesMom));
+           }
+      
+           friend std::ostream& operator << (std::ostream&        out,
+                                             const lorentzVector& vec)
+           {
+                   out << "(" << vec.GetPx() << ", " << vec.GetPy() << ", " << vec.GetPz()
+                       << "; " << vec.GetE() << ")";
+                   return out;
+           }
+
+   private:
+      
+      vector3 fSpaceVec;
+      double fTime;
+      
+};
+
+
+#endif  // LORENTZVECTOR_H