MathConstants.hh

#ifndef RIVET_Math_MathConstants
#define RIVET_Math_MathConstants
 
#include "Rivet/Tools/Exceptions.hh"
#include "Rivet/Tools/Utils.hh"
#include <cmath>
 
namespace Rivet {
 
 
  constexpr double PI = M_PI;
 
  constexpr double TWOPI = 2*M_PI;
 
  constexpr double HALFPI = M_PI_2;
 
  constexpr double SQRT2 = M_SQRT2;
 
  constexpr double SQRTPI = 2 / M_2_SQRTPI;
 
  // /// A pre-defined value of \f$ \sqrt{2\pi} \f$.
  // constexpr double SQRT2PI = SQRT2 * SQRTPI;
 
  constexpr double INFF = HUGE_VALF;
  constexpr double INF = HUGE_VAL;
  constexpr double INFL = HUGE_VALL;
 
  // Other useful predefined values already exist in C++, e.g.:
  // DBL_MAX
  // NAN
 
 
  enum Sign { MINUS = -1, ZERO = 0, PLUS = 1 };
 
  enum RapScheme { PSEUDORAPIDITY = 0, ETARAP = 0, RAPIDITY = 1, YRAP = 1 };
 
  enum PhiMapping { MINUSPI_PLUSPI, ZERO_2PI, ZERO_PI };
 
}
 
#endif