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//
// $Id: G4PhysicsVector.cc,v 1.22 2008/09/05 18:04:45 vnivanch Exp $
// GEANT4 tag $Name: HEAD $
//
// 
// --------------------------------------------------------------
//      GEANT 4 class implementation file
//
//  G4PhysicsVector.cc
//
//  History:
//    02 Dec. 1995, G.Cosmo : Structure created based on object model
//    03 Mar. 1996, K.Amako : Implemented the 1st version
//    01 Jul. 1996, K.Amako : Hidden bin from the user introduced
//    12 Nov. 1998, K.Amako : A bug in GetVectorLength() fixed
//    11 Nov. 2000, H.Kurashige : use STL vector for dataVector and binVector
//    18 Jan. 2001, H.Kurashige : removed ptrNextTable
//    09 Mar. 2001, H.Kurashige : added G4PhysicsVector type 
//    05 Sep. 2008, V.Ivanchenko : added protections for zero-length vector
// --------------------------------------------------------------

#include "G4PhysicsVector.hh"
#include <iomanip>

// --------------------------------------------------------------

G4PhysicsVector::G4PhysicsVector(G4bool spline)
 : type(T_G4PhysicsVector),
   edgeMin(DBL_MAX), edgeMax(0.), numberOfBin(0),
   lastEnergy(0.), lastValue(0.), lastBin(0), 
   secDerivative(0), useSpline(spline)
{
  binVector.push_back(edgeMin);
  dataVector.push_back(0.0);
}

// --------------------------------------------------------------

G4PhysicsVector::~G4PhysicsVector() 
{
  delete [] secDerivative;
}

// --------------------------------------------------------------

G4PhysicsVector::G4PhysicsVector(const G4PhysicsVector& right)
{
  *this=right;
}

// --------------------------------------------------------------

G4PhysicsVector& G4PhysicsVector::operator=(const G4PhysicsVector& right)
{
  if (&right==this)  { return *this; }
  if (type != right.type)  { return *this; }

  type = right.type;
  edgeMin = right.edgeMin;
  edgeMax = right.edgeMax;
  numberOfBin = right.numberOfBin;
  lastEnergy = right.lastEnergy;
  lastValue = right.lastValue;
  lastBin = right.lastBin;
  dataVector = right.dataVector;
  binVector = right.binVector;
  secDerivative = right.secDerivative;
  useSpline = right.useSpline;
  comment = right.comment;
  return *this;
}

// --------------------------------------------------------------

G4int G4PhysicsVector::operator==(const G4PhysicsVector &right) const
{
  return (this == &right);
}

// --------------------------------------------------------------

G4int G4PhysicsVector::operator!=(const G4PhysicsVector &right) const
{
  return (this != &right);
}

// --------------------------------------------------------------

G4double G4PhysicsVector::GetLowEdgeEnergy(size_t binNumber) const
{
  return binVector[binNumber];
}

// --------------------------------------------------------------

G4bool G4PhysicsVector::Store(std::ofstream& fOut, G4bool ascii)
{
  // Ascii mode
  if (ascii)
  {
    fOut << *this;
    return true;
  } 
  // Binary Mode

  // binning
  fOut.write((char*)(&edgeMin), sizeof edgeMin);
  fOut.write((char*)(&edgeMax), sizeof edgeMax);
  fOut.write((char*)(&numberOfBin), sizeof numberOfBin);

  // contents
  size_t size = dataVector.size(); 
  fOut.write((char*)(&size), sizeof size);

  G4double* value = new G4double[2*size];
  for(size_t i = 0; i < size; i++)
  {
    value[2*i]  =  binVector[i];
    value[2*i+1]=  dataVector[i];
  }
  fOut.write((char*)(value), 2*size*(sizeof (G4double)));
  delete [] value;

  return true;
}

// --------------------------------------------------------------

G4bool G4PhysicsVector::Retrieve(std::ifstream& fIn, G4bool ascii)
{
  // clear properties;
  lastEnergy=0.;
  lastValue =0.;
  lastBin   =0;
  dataVector.clear();
  binVector.clear();
  comment = "";

  // retrieve in ascii mode
  if (ascii)
  {
    // binning
    fIn >> edgeMin >> edgeMax >> numberOfBin; 
    if (fIn.fail())  { return false; }
    // contents
    size_t size=0;
    fIn >> size;
    if (fIn.fail())  { return false; }

    binVector.reserve(size);
    dataVector.reserve(size);
    G4double vBin, vData;

    for(size_t i = 0; i < size ; i++)
    {
      vBin = 0.;
      vData= 0.;
      fIn >> vBin >> vData;
      if (fIn.fail())  { return false; }
      binVector.push_back(vBin);
      dataVector.push_back(vData);
    }
    return true ;
  }

  // retrieve in binary mode
  // binning
  fIn.read((char*)(&edgeMin), sizeof edgeMin);
  fIn.read((char*)(&edgeMax), sizeof edgeMax);
  fIn.read((char*)(&numberOfBin), sizeof numberOfBin ); 
 
  // contents
  size_t size;
  fIn.read((char*)(&size), sizeof size); 
 
  G4double* value = new G4double[2*size];
  fIn.read((char*)(value),  2*size*(sizeof(G4double)) );
  if (G4int(fIn.gcount()) != G4int(2*size*(sizeof(G4double))) )
  {
    delete [] value;
    return false;
  }

  binVector.reserve(size);
  dataVector.reserve(size);
  for(size_t i = 0; i < size; i++)
  {
    binVector.push_back(value[2*i]);
    dataVector.push_back(value[2*i+1]);
  }
  delete [] value;
  return true;
}

// --------------------------------------------------------------

void G4PhysicsVector::FillSecondDerivatives()
{  
  secDerivative = new G4double [numberOfBin];

  secDerivative[0] = 0.0 ;

  // cannot compute derivatives for less than 3 points
  if(3 > numberOfBin) {
    secDerivative[numberOfBin-1] = 0.0 ;
    return;
  }

  G4double* u = new G4double [numberOfBin];
  u[0] = 0.0 ;
   
  // Decomposition loop for tridiagonal algorithm. secDerivative[i]
  // and u[i] are used for temporary storage of the decomposed factors.
   
  for(size_t i=1; i<numberOfBin-1; i++)
  {
    G4double sig = (binVector[i]-binVector[i-1])
                 / (binVector[i+1]-binVector[i-1]) ;
    G4double p = sig*secDerivative[i-1] + 2.0 ;
    secDerivative[i] = (sig - 1.0)/p ;
    u[i] = (dataVector[i+1]-dataVector[i])/(binVector[i+1]-binVector[i])
         - (dataVector[i]-dataVector[i-1])/(binVector[i]-binVector[i-1]) ;
    u[i] =(6.0*u[i]/(binVector[i+1]-binVector[i-1]) - sig*u[i-1])/p ;
  }

  G4double qn = 0.0 ;
  G4double un = 0.0 ;

  secDerivative[numberOfBin-1] = (un - qn*u[numberOfBin-2])
                               / (qn*secDerivative[numberOfBin-2] + 1.0) ;
   
  // The back-substitution loop for the triagonal algorithm of solving
  // a linear system of equations.
   
  for(G4int k=numberOfBin-2; k>=0; k--)
  {
    secDerivative[k] = secDerivative[k]*secDerivative[k+1] + u[k];
  }
  delete [] u;
}
   
// --------------------------------------------------------------

std::ostream& operator<<(std::ostream& out, const G4PhysicsVector& pv)
{
  // binning
  out << std::setprecision(12) << pv.edgeMin;
  out <<" " << pv.edgeMax <<" "  << pv.numberOfBin << G4endl; 

  // contents
  out << pv.dataVector.size() << G4endl; 
  for(size_t i = 0; i < pv.dataVector.size(); i++)
  {
    out << std::setprecision(12) << pv.binVector[i] << "  "
        << pv.dataVector[i] << G4endl;
  }
  return out;
}