// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4PhysicsVector.icc,v 1.1 1999/11/16 17:40:46 gcosmo Exp $
// GEANT4 tag $Name: geant4-02-00 $
//
// 
//---------------------------------------------------------------
//      GEANT 4 class source file
//
//  G4PhysicsVector.icc
//
//  Description:
//    A physics vector which has values of energy-loss, cross-section, 
//    and other physics values of a particle in matter in a given 
//    range of the energy, momentum, etc.
//    This class serves as the base class for a vector having various 
//    energy scale, for example like 'log', 'linear', 'free', etc.
//
//---------------------------------------------------------------


inline G4double G4PhysicsVector::operator[](const size_t binNumber) const
{
  return dataVector[binNumber];
}


inline G4double G4PhysicsVector::operator()(const size_t binNumber) const
{
  return dataVector(binNumber);
}


inline const G4RWTPtrOrderedVector<G4PhysicsVector>*
G4PhysicsVector::GetNextTable() const
{
  return ptrNextTable;
}


inline G4double G4PhysicsVector::LinearInterpolation(G4double theEnergy, 
                                                     size_t theLocBin) {

  // Linear interpolation is used to get the value. If the give energy
  // is in the highest bin, no interpolation will be Done. Because 
  // there is an extra bin hidden from a user at locBin=numberOfBin, 
  // the following interpolation is valid even the current locBin=
  // numberOfBin-1. 

  G4double intplFactor = (theEnergy-binVector(theLocBin)) 
     / (binVector(theLocBin+1)-binVector(theLocBin)); // Interpolation factor

  return dataVector(theLocBin) +
         ( dataVector(theLocBin+1)-dataVector(theLocBin) ) * intplFactor;
}


inline G4double G4PhysicsVector::GetValue(G4double theEnergy, 
                                          G4bool& isOutRange) {

  // Use cache for speed up - check if the value 'theEnergy' is same as the 
  // last call. If it is same, then use the last bin location. Also the
  // value 'theEnergy' lies between the last energy and low edge of of the 
  // bin of last call, then the last bin location is used.

  isOutRange = false;                // No range check. 

  size_t locBin;

  if( theEnergy == lastEnergy ) {
     return lastValue;        
  } 
  else if( (theEnergy < lastEnergy) && 
           (theEnergy >= binVector(lastBin)) ) {
     locBin = lastBin;

     lastEnergy = theEnergy;
     lastValue = LinearInterpolation(theEnergy, locBin);
     return lastValue;
  } 
  else if( theEnergy < edgeMin ){
     lastBin = 0;
     lastEnergy = theEnergy;
     lastValue = dataVector(0);
     return lastValue;
  } 
  else if( theEnergy >= edgeMax ){
     lastBin = numberOfBin-1;
     lastEnergy = theEnergy;
     lastValue = dataVector( numberOfBin-1 );
     return lastValue;
  } 
  else {
     locBin = FindBinLocation(theEnergy); 

     lastBin = locBin;
     lastEnergy = theEnergy;
     lastValue = LinearInterpolation(theEnergy, locBin);
     return lastValue;
  }
}
