G4SPSEneDistribution.cc

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//
//
// MODULE:        G4SPSEneDistribution.cc
//
// Version:      1.0
// Date:         5/02/04
// Author:       Fan Lei 
// Organisation: QinetiQ ltd.
// Customer:     ESA/ESTEC
//
//
// CHANGE HISTORY
// --------------
//
//
// Version 1.0, 05/02/2004, Fan Lei, Created.
//    Based on the G4GeneralParticleSource class in Geant4 v6.0
//
//
//  26/03/2014, Andrew Green.
//      Modification to used STL vectors instead of C-style arrays. This should save some space,
//      particularly when the blackbody function is not used. Also moved to dynamically allocated
//      memory in the LinearInterpolation, ExpInterpolation and LogInterpolation functions. Again,
//      this will save space if these functions are unused.
//
//
// 24/11/2017  Fan Lei
//    Added cutoff power-law distribution option. Implementation is similar to that of the BlackBody one.
#include "G4SPSEneDistribution.hh"

#include "G4Exp.hh"
#include "G4SystemOfUnits.hh"
#include "Randomize.hh"
#include "G4AutoLock.hh"
#include "G4Threading.hh"

G4SPSEneDistribution::G4SPSEneDistribution(): Epnflag(false),eneRndm(0),Splinetemp(0)
{
    G4MUTEXINIT(mutex);
  //
  // Initialise all variables
  particle_energy = 1.0 * MeV;
  EnergyDisType = "Mono";
  weight=1.;
  MonoEnergy = 1 * MeV;
  Emin = 0.;
  Emax = 1.e30;
  alpha = 0.;
  biasalpha = 0.;
    prob_norm = 1.0;
  Ezero = 0.;
  SE = 0.;
  Temp = 0.;
  grad = 0.;
  cept = 0.;
  Biased = false; // not biased
  EnergySpec = true; // true - energy spectra, false - momentum spectra
  DiffSpec = true; // true - differential spec, false integral spec
  IntType = "NULL"; // Interpolation type
  IPDFEnergyExist = false;
  IPDFArbExist = false;

  ArbEmin = 0.;
  ArbEmax = 1.e30;

  verbosityLevel = 0;
    
    //AG: Set these pointers to NULL so we know if they were used...
    Arb_grad = NULL;
    Arb_cept = NULL;
    Arb_alpha = NULL;
    Arb_Const = NULL;
    Arb_ezero = NULL;
    Arb_grad_cept_flag = false;
    Arb_alpha_Const_flag = false;
    Arb_ezero_flag = false;
    BBhistInit = false;
    BBhistCalcd = false;
    CPhistInit = false;
    CPhistCalcd = false;
    
    BBHist = NULL;
    Bbody_x = NULL;
    CPHist = NULL;
    CP_x = NULL;

    threadLocal_t& data = threadLocalData.Get();
    data.Emax = Emax;
    data.Emin = Emin;
    data.alpha =alpha;
    data.cept = cept;
    data.Ezero = Ezero;
    data.grad = grad;
    data.particle_energy = 0;
    data.particle_definition = NULL;
    data.weight = weight;
}

G4SPSEneDistribution::~G4SPSEneDistribution()
{
    G4MUTEXDESTROY(mutex);
    if(Arb_grad_cept_flag)
    {
        delete[] Arb_grad;
        delete[] Arb_cept;
    }
    
    if(Arb_alpha_Const_flag)
    {
        delete[] Arb_alpha;
        delete[] Arb_Const;
    }
    
    if(Arb_ezero_flag)
    {
        delete[] Arb_ezero;
    }
    delete Bbody_x;
    delete BBHist;
    delete CP_x;
    delete CPHist;
    for ( std::vector<G4DataInterpolation*>::iterator it = SplineInt.begin() ; it!=SplineInt.end() ; ++it)
    {
        delete *it;
        *it = 0;
    }
    SplineInt.clear();
}

void G4SPSEneDistribution::SetEnergyDisType(G4String DisType) {
    G4AutoLock l(&mutex);
  EnergyDisType = DisType;
  if (EnergyDisType == "User")
    {
    UDefEnergyH = IPDFEnergyH = ZeroPhysVector;
    IPDFEnergyExist = false;
  }
    else if (EnergyDisType == "Arb")
    {
    ArbEnergyH = IPDFArbEnergyH = ZeroPhysVector;
    IPDFArbExist = false;
  }
    else if (EnergyDisType == "Epn")
    {
    UDefEnergyH = IPDFEnergyH = ZeroPhysVector;
    IPDFEnergyExist = false;
    EpnEnergyH = ZeroPhysVector;
  }
}

G4String G4SPSEneDistribution::GetEnergyDisType()
{
    G4AutoLock l(&mutex);
    return EnergyDisType;
}

void G4SPSEneDistribution::SetEmin(G4double emi) {
    G4AutoLock l(&mutex);
  Emin = emi;
    threadLocalData.Get().Emin = Emin;
}

G4double G4SPSEneDistribution::GetEmin()
{
    return threadLocalData.Get().Emin;
}

G4double G4SPSEneDistribution::GetArbEmin()
{
    G4AutoLock l(&mutex);
    return ArbEmin;
}

G4double G4SPSEneDistribution::GetArbEmax()
{
    G4AutoLock l(&mutex);
    return ArbEmax;
}

void G4SPSEneDistribution::SetEmax(G4double ema) {
    G4AutoLock l(&mutex);
  Emax = ema;
    threadLocalData.Get().Emax = Emax;
}

G4double G4SPSEneDistribution::GetEmax()
{
    return threadLocalData.Get().Emax;
}


void G4SPSEneDistribution::SetMonoEnergy(G4double menergy) {
    G4AutoLock l(&mutex);
  MonoEnergy = menergy;
}

void G4SPSEneDistribution::SetBeamSigmaInE(G4double e) {
    G4AutoLock l(&mutex);
  SE = e;
}
void G4SPSEneDistribution::SetAlpha(G4double alp) {
    G4AutoLock l(&mutex);
  alpha = alp;
    threadLocalData.Get().alpha = alpha;
}

void G4SPSEneDistribution::SetBiasAlpha(G4double alp) {
    G4AutoLock l(&mutex);
  biasalpha = alp;
  Biased = true;
}

void G4SPSEneDistribution::SetTemp(G4double tem) {
  G4AutoLock l(&mutex);
    Temp = tem;
}

void G4SPSEneDistribution::SetEzero(G4double eze) {
  G4AutoLock l(&mutex);
    Ezero = eze;
    threadLocalData.Get().Ezero = Ezero;
}

void G4SPSEneDistribution::SetGradient(G4double gr) {
  G4AutoLock l(&mutex);
    grad = gr;
    threadLocalData.Get().grad = grad;
}

void G4SPSEneDistribution::SetInterCept(G4double c) {
  G4AutoLock l(&mutex);
    cept = c;
    threadLocalData.Get().cept = cept;
}

G4String G4SPSEneDistribution::GetIntType()
{
  G4AutoLock l(&mutex);
    return IntType;
}

void G4SPSEneDistribution::SetBiasRndm(G4SPSRandomGenerator* a)
{
    G4AutoLock l(&mutex);
    eneRndm = a;
}

void G4SPSEneDistribution::SetVerbosity(G4int a)
{
    G4AutoLock l(&mutex);
    verbosityLevel = a;
}

G4double G4SPSEneDistribution::GetWeight()
{
    return threadLocalData.Get().weight;
}

G4double G4SPSEneDistribution::GetMonoEnergy()
{
    G4AutoLock l(&mutex);
    return MonoEnergy;
}

G4double G4SPSEneDistribution::GetSE()
{
    G4AutoLock l(&mutex);
    return SE;
}

G4double G4SPSEneDistribution::Getalpha()
{
    return threadLocalData.Get().alpha;
}

G4double G4SPSEneDistribution::GetEzero()
{
    return threadLocalData.Get().Ezero;
}

G4double G4SPSEneDistribution::GetTemp()
{
    G4AutoLock l(&mutex);
    return Temp;
}

G4double G4SPSEneDistribution::Getgrad()
{
    return threadLocalData.Get().grad;
}

G4double G4SPSEneDistribution::Getcept()
{
    return threadLocalData.Get().cept;
}

G4PhysicsOrderedFreeVector G4SPSEneDistribution::GetUserDefinedEnergyHisto()
{
    G4AutoLock l(&mutex);
    return UDefEnergyH;
}

G4PhysicsOrderedFreeVector G4SPSEneDistribution::GetArbEnergyHisto()
{
    G4AutoLock l(&mutex);
    return ArbEnergyH;
}

void G4SPSEneDistribution::UserEnergyHisto(G4ThreeVector input) {
  G4AutoLock l(&mutex);
    G4double ehi, val;
  ehi = input.x();
  val = input.y();
  if (verbosityLevel > 1) {
    G4cout << "In UserEnergyHisto" << G4endl;
    G4cout << " " << ehi << " " << val << G4endl;
  }
  UDefEnergyH.InsertValues(ehi, val);
  Emax = ehi;
    threadLocalData.Get().Emax = Emax;
}

void G4SPSEneDistribution::ArbEnergyHisto(G4ThreeVector input)
{
    G4AutoLock l(&mutex);
  G4double ehi, val;
  ehi = input.x();
  val = input.y();
  if (verbosityLevel > 1)
    {
    G4cout << "In ArbEnergyHisto" << G4endl;
    G4cout << " " << ehi << " " << val << G4endl;
  }
  ArbEnergyH.InsertValues(ehi, val);
}

void G4SPSEneDistribution::ArbEnergyHistoFile(G4String filename)
{
    G4AutoLock l(&mutex);
  std::ifstream infile(filename, std::ios::in);
  if (!infile)
    {
    G4Exception("G4SPSEneDistribution::ArbEnergyHistoFile","Event0301",FatalException,"Unable to open the histo ASCII file");
    }
  G4double ehi, val;
  while (infile >> ehi >> val)
    {
    ArbEnergyH.InsertValues(ehi, val);
  }
}

void G4SPSEneDistribution::EpnEnergyHisto(G4ThreeVector input)
{
    G4AutoLock l(&mutex);
  G4double ehi, val;
  ehi = input.x();
  val = input.y();
  if (verbosityLevel > 1)
    {
    G4cout << "In EpnEnergyHisto" << G4endl;
    G4cout << " " << ehi << " " << val << G4endl;
  }
  EpnEnergyH.InsertValues(ehi, val);
  Emax = ehi;
    threadLocalData.Get().Emax = Emax;
  Epnflag = true;
}

void G4SPSEneDistribution::Calculate()
{
    G4AutoLock l(&mutex);
  if (EnergyDisType == "Cdg")
    {
    CalculateCdgSpectrum();
    }
  else if (EnergyDisType == "Bbody")
    {
        if(!BBhistInit)
        {
            BBInitHists();
        }
    CalculateBbodySpectrum();
    }
  else if (EnergyDisType == "CPow")
    {
        if(!CPhistInit)
        {
            CPInitHists();
        }
    CalculateCPowSpectrum();
    }
}

//MT: Lock in caller
void G4SPSEneDistribution::BBInitHists()
{
    BBHist = new std::vector<G4double>(10001, 0.0);
    Bbody_x = new std::vector<G4double>(10001, 0.0);
    BBhistInit = true;
}

//MT: Lock in caller
void G4SPSEneDistribution::CPInitHists()
{
    CPHist = new std::vector<G4double>(10001, 0.0);
    CP_x = new std::vector<G4double>(10001, 0.0);
    CPhistInit = true;
}


//MT: Lock in caller
void G4SPSEneDistribution::CalculateCdgSpectrum()
{
  // This uses the spectrum from The INTEGRAL Mass Model (TIMM)
  // to generate a Cosmic Diffuse X/gamma ray spectrum.
  G4double pfact[2] = { 8.5, 112 };
  G4double spind[2] = { 1.4, 2.3 };
  G4double ene_line[3] = { 1. * keV, 18. * keV, 1E6 * keV };
  G4int n_par;

  ene_line[0] = threadLocalData.Get().Emin;
  if (threadLocalData.Get().Emin < 18 * keV)
    {
    n_par = 2;
    ene_line[2] = threadLocalData.Get().Emax;
    if (threadLocalData.Get().Emax < 18 * keV)
        {
      n_par = 1;
      ene_line[1] = threadLocalData.Get().Emax;
    }
  }
    else
    {
    n_par = 1;
    pfact[0] = 112.;
    spind[0] = 2.3;
    ene_line[1] = threadLocalData.Get().Emax;
  }

  // Create a cumulative histogram.
  CDGhist[0] = 0.;
  G4double omalpha;
  G4int i = 0;

  while (i < n_par)
    {
    omalpha = 1. - spind[i];
    CDGhist[i + 1] = CDGhist[i] + (pfact[i] / omalpha) * (std::pow(ene_line[i + 1] / keV, omalpha) - std::pow(ene_line[i] / keV,omalpha));
    i++;
  }

  // Normalise histo and divide by 1000 to make MeV.
  i = 0;
  while (i < n_par)
    {
    CDGhist[i + 1] = CDGhist[i + 1] / CDGhist[n_par];
    //      G4cout << CDGhist[i] << CDGhist[n_par] << G4endl;
    i++;
  }
}

//MT: Lock in caller
void G4SPSEneDistribution::CalculateBbodySpectrum()
{
  // create bbody spectrum
  // Proved very hard to integrate indefinitely, so different
  // method. User inputs emin, emax and T. These are used to
  // create a 10,000 bin histogram.
  // Use photon density spectrum = 2 nu**2/c**2 * (std::exp(h nu/kT)-1)
  // = 2 E**2/h**2c**2 times the exponential
    
  G4double erange = threadLocalData.Get().Emax - threadLocalData.Get().Emin;
  G4double steps = erange / 10000.;
    
  const G4double k = 8.6181e-11; //Boltzmann const in MeV/K
  const G4double h = 4.1362e-21; // Plancks const in MeV s
  const G4double c = 3e8; // Speed of light
  const G4double h2 = h * h;
  const G4double c2 = c * c;
  G4int count = 0;
  G4double sum = 0.;
  BBHist->at(0) = 0.;
    
  while (count < 10000) {
    Bbody_x->at(count) = threadLocalData.Get().Emin + G4double(count * steps);
        G4double Bbody_y = (2. * std::pow(Bbody_x->at(count), 2.)) / (h2 * c2 * (std::exp(Bbody_x->at(count) / (k * Temp)) - 1.));
    sum = sum + Bbody_y;
    BBHist->at(count + 1) = BBHist->at(count) + Bbody_y;
        count++;
  }

  Bbody_x->at(10000) = threadLocalData.Get().Emax;
  // Normalise cumulative histo.
  count = 0;
  while (count < 10001) {
    BBHist->at(count) = BBHist->at(count) / sum;
    count++;
  }
}

//MT: Lock in caller
void G4SPSEneDistribution::CalculateCPowSpectrum()
{
  // create cutoff power-law spectrum
  // x^a exp(-x/b)
  // the integral of this function is an incomplete gamma function, which is only available in the Boost library.
    // 
  // User inputs are emin, emax and alpha and Ezero. These are used to
  // create a 10,000 bin histogram.
    
  G4double erange = threadLocalData.Get().Emax - threadLocalData.Get().Emin;
  G4double steps = erange / 10000.;
  alpha = threadLocalData.Get().alpha ;
  Ezero = threadLocalData.Get().Ezero ;
    
  G4int count = 0;
  G4double sum = 0.;
  CPHist->at(0) = 0.;
    
  while (count < 10000) {
    CP_x->at(count) = threadLocalData.Get().Emin + G4double(count * steps);
        G4double CP_y = std::pow(CP_x->at(count), alpha) * std::exp(-CP_x->at(count) / Ezero);
    sum = sum + CP_y;
    CPHist->at(count + 1) = CPHist->at(count) + CP_y;
        count++;
  }

  CP_x->at(10000) = threadLocalData.Get().Emax;
  // Normalise cumulative histo.
  count = 0;
  while (count < 10001) {
    CPHist->at(count) = CPHist->at(count) / sum;
    count++;
  }
}

void G4SPSEneDistribution::InputEnergySpectra(G4bool value) {
    G4AutoLock l(&mutex);
  // Allows user to specifiy spectrum is momentum
  EnergySpec = value; // false if momentum
  if (verbosityLevel > 1)
    G4cout << "EnergySpec has value " << EnergySpec << G4endl;
}

void G4SPSEneDistribution::InputDifferentialSpectra(G4bool value) {
    G4AutoLock l(&mutex);
  // Allows user to specify integral or differential spectra
  DiffSpec = value; // true = differential, false = integral
  if (verbosityLevel > 1)
    G4cout << "Diffspec has value " << DiffSpec << G4endl;
}

void G4SPSEneDistribution::ArbInterpolate(G4String IType) {
    G4AutoLock l(&mutex);
  if (EnergyDisType != "Arb")
        G4Exception("G4SPSEneDistribution::ArbInterpolate",
                    "Event0302",FatalException,
              "Error: this is for arbitrary distributions");
  IntType = IType;
  ArbEmax = ArbEnergyH.GetMaxLowEdgeEnergy();
  ArbEmin = ArbEnergyH.GetMinLowEdgeEnergy();

  // Now interpolate points
  if (IntType == "Lin")
    LinearInterpolation();
  if (IntType == "Log")
    LogInterpolation();
  if (IntType == "Exp")
    ExpInterpolation();
  if (IntType == "Spline")
    SplineInterpolation();
}

//MT: Lock in caller
void G4SPSEneDistribution::LinearInterpolation() {
  // Method to do linear interpolation on the Arb points
  // Calculate equation of each line segment, max 1024.
  // Calculate Area under each segment
  // Create a cumulative array which is then normalised Arb_Cum_Area

  G4double Area_seg[1024]; // Stores area under each segment
  G4double sum = 0., Arb_x[1024], Arb_y[1024], Arb_Cum_Area[1024];
  G4int i, count;
  G4int maxi = ArbEnergyH.GetVectorLength();
  for (i = 0; i < maxi; i++)
    {
    Arb_x[i] = ArbEnergyH.GetLowEdgeEnergy(size_t(i));
    Arb_y[i] = ArbEnergyH(size_t(i));
  }
  // Points are now in x,y arrays. If the spectrum is integral it has to be
  // made differential and if momentum it has to be made energy.
  if (DiffSpec == false)
    {
    // Converts integral point-wise spectra to Differential
    for (count = 0; count < maxi - 1; count++)
        {
      Arb_y[count] = (Arb_y[count] - Arb_y[count + 1])
          / (Arb_x[count + 1] - Arb_x[count]);
    }
    maxi--;
  }
  //
  if (EnergySpec == false)
    {
    // change currently stored values (emin etc) which are actually momenta
    // to energies.
        G4ParticleDefinition* pdef =threadLocalData.Get().particle_definition;
    if (pdef == NULL)
        {
            G4Exception("G4SPSEneDistribution::LinearInterpolation",
                        "Event0302",FatalException,
                        "Error: particle not defined");
        }
    else
        {
      // Apply Energy**2 = p**2c**2 + m0**2c**4
      // p should be entered as E/c i.e. without the division by c
      // being done - energy equivalent.
      G4double mass = pdef->GetPDGMass();
      // convert point to energy unit and its value to per energy unit
      G4double total_energy;
      for (count = 0; count < maxi; count++)
            {
        total_energy = std::sqrt((Arb_x[count] * Arb_x[count]) + (mass
            * mass)); // total energy

        Arb_y[count] = Arb_y[count] * Arb_x[count] / total_energy;
        Arb_x[count] = total_energy - mass; // kinetic energy
      }
    }
  }
  //
  i = 1;
    // AG:
    // This *should* be the first use of Arb_grad and friends, so we *should* be able to
    // dynamically allocate here
    Arb_grad = new G4double [1024];
    Arb_cept = new G4double [1024];
    Arb_grad_cept_flag = true;
    
  Arb_grad[0] = 0.;
  Arb_cept[0] = 0.;
  Area_seg[0] = 0.;
  Arb_Cum_Area[0] = 0.;
  while (i < maxi)
    {
    // calc gradient and intercept for each segment
    Arb_grad[i] = (Arb_y[i] - Arb_y[i - 1]) / (Arb_x[i] - Arb_x[i - 1]);
    if (verbosityLevel == 2)
        {
      G4cout << Arb_grad[i] << G4endl;
        }
    if (Arb_grad[i] > 0.)
        {
      if (verbosityLevel == 2)
            {
        G4cout << "Arb_grad is positive" << G4endl;
            }
      Arb_cept[i] = Arb_y[i] - (Arb_grad[i] * Arb_x[i]);
    }
        else if (Arb_grad[i] < 0.)
        {
      if (verbosityLevel == 2)
            {
        G4cout << "Arb_grad is negative" << G4endl;
            }
      Arb_cept[i] = Arb_y[i] + (-Arb_grad[i] * Arb_x[i]);
    }
        else
        {
      if (verbosityLevel == 2)
            {
        G4cout << "Arb_grad is 0." << G4endl;
            }
      Arb_cept[i] = Arb_y[i];
    }

    Area_seg[i] = ((Arb_grad[i] / 2) * (Arb_x[i] * Arb_x[i] - Arb_x[i - 1] * Arb_x[i - 1]) + Arb_cept[i] * (Arb_x[i] - Arb_x[i - 1]));
    Arb_Cum_Area[i] = Arb_Cum_Area[i - 1] + Area_seg[i];
    sum = sum + Area_seg[i];
    if (verbosityLevel == 2)
        {
      G4cout << Arb_x[i] << Arb_y[i] << Area_seg[i] << sum << Arb_grad[i] << G4endl;
        }
    i++;
  }

  i = 0;
  while (i < maxi)
    {
    Arb_Cum_Area[i] = Arb_Cum_Area[i] / sum; // normalisation
    IPDFArbEnergyH.InsertValues(Arb_x[i], Arb_Cum_Area[i]);
    i++;
  }

  // now scale the ArbEnergyH, needed by Probability()
  ArbEnergyH.ScaleVector(1., 1./sum);

  if (verbosityLevel >= 1)
    {
    G4cout << "Leaving LinearInterpolation" << G4endl;
    ArbEnergyH.DumpValues();
    IPDFArbEnergyH.DumpValues();
  }
}

//MT: Lock in caller
void G4SPSEneDistribution::LogInterpolation()
{
  // Interpolation based on Logarithmic equations
  // Generate equations of line segments
  // y = Ax**alpha => log y = alpha*logx + logA
  // Find area under line segments
  // create normalised, cumulative array Arb_Cum_Area
  G4double Area_seg[1024]; // Stores area under each segment
  G4double sum = 0., Arb_x[1024], Arb_y[1024], Arb_Cum_Area[1024];
  G4int i, count;
  G4int maxi = ArbEnergyH.GetVectorLength();
  for (i = 0; i < maxi; i++)
    {
    Arb_x[i] = ArbEnergyH.GetLowEdgeEnergy(size_t(i));
    Arb_y[i] = ArbEnergyH(size_t(i));
  }
  // Points are now in x,y arrays. If the spectrum is integral it has to be
  // made differential and if momentum it has to be made energy.
  if (DiffSpec == false)
    {
    // Converts integral point-wise spectra to Differential
    for (count = 0; count < maxi - 1; count++)
        {
      Arb_y[count] = (Arb_y[count] - Arb_y[count + 1]) / (Arb_x[count + 1] - Arb_x[count]);
    }
    maxi--;
  }
  //
  if (EnergySpec == false)
    {
    // change currently stored values (emin etc) which are actually momenta
    // to energies.
        G4ParticleDefinition* pdef = threadLocalData.Get().particle_definition;
    if (pdef == NULL)
        {
            G4Exception("G4SPSEneDistribution::LogInterpolation",
                        "Event0302",FatalException,
                        "Error: particle not defined");
        }
    else
        {
      // Apply Energy**2 = p**2c**2 + m0**2c**4
      // p should be entered as E/c i.e. without the division by c
      // being done - energy equivalent.
      G4double mass = pdef->GetPDGMass();
      // convert point to energy unit and its value to per energy unit
      G4double total_energy;
      for (count = 0; count < maxi; count++)
            {
        total_energy = std::sqrt((Arb_x[count] * Arb_x[count]) + (mass
            * mass)); // total energy

        Arb_y[count] = Arb_y[count] * Arb_x[count] / total_energy;
        Arb_x[count] = total_energy - mass; // kinetic energy
      }
    }
  }
  //
  i = 1;
    
    //AG:  *Should* be the first use of these two arrays
    if ( Arb_ezero ) { delete[] Arb_ezero; Arb_ezero = 0; }
    if ( Arb_Const ) { delete[] Arb_Const; Arb_Const = 0; }
    Arb_alpha = new G4double [1024];
    Arb_Const = new G4double [1024];
    Arb_alpha_Const_flag = true;
    
    
  Arb_alpha[0] = 0.;
  Arb_Const[0] = 0.;
  Area_seg[0] = 0.;
  Arb_Cum_Area[0] = 0.;
  if (Arb_x[0] <= 0. || Arb_y[0] <= 0.)
    {
    G4cout << "You should not use log interpolation with points <= 0." << G4endl;
    G4cout << "These will be changed to 1e-20, which may cause problems" << G4endl;
    if (Arb_x[0] <= 0.)
        {
      Arb_x[0] = 1e-20;
        }
    if (Arb_y[0] <= 0.)
        {
      Arb_y[0] = 1e-20;
        }
  }

  G4double alp;
  while (i < maxi)
    {
    // Incase points are negative or zero
    if (Arb_x[i] <= 0. || Arb_y[i] <= 0.)
        {
      G4cout << "You should not use log interpolation with points <= 0." << G4endl;
      G4cout << "These will be changed to 1e-20, which may cause problems" << G4endl;
      if (Arb_x[i] <= 0.)
            {
        Arb_x[i] = 1e-20;
            }
      if (Arb_y[i] <= 0.)
            {
        Arb_y[i] = 1e-20;
            }
    }

    Arb_alpha[i] = (std::log10(Arb_y[i]) - std::log10(Arb_y[i - 1])) / (std::log10(Arb_x[i]) - std::log10(Arb_x[i - 1]));
    Arb_Const[i] = Arb_y[i] / (std::pow(Arb_x[i], Arb_alpha[i]));
    alp = Arb_alpha[i] + 1;
    if (alp == 0.)
        {
      Area_seg[i] = Arb_Const[i] * (std::log(Arb_x[i]) - std::log(Arb_x[i - 1])); 
    }
        else
        {
      Area_seg[i] = (Arb_Const[i] / alp) * (std::pow(Arb_x[i], alp) - std::pow(Arb_x[i - 1], alp));
    }
    sum = sum + Area_seg[i];
    Arb_Cum_Area[i] = Arb_Cum_Area[i - 1] + Area_seg[i];
    if (verbosityLevel == 2)
        {
      G4cout << Arb_alpha[i] << Arb_Const[i] << Area_seg[i] << G4endl;
        }
    i++;
  }

  i = 0;
  while (i < maxi)
    {
    Arb_Cum_Area[i] = Arb_Cum_Area[i] / sum;
    IPDFArbEnergyH.InsertValues(Arb_x[i], Arb_Cum_Area[i]);
    i++;
  }

  // now scale the ArbEnergyH, needed by Probability()
  ArbEnergyH.ScaleVector(1., 1./sum);

  if (verbosityLevel >= 1)
    {
    G4cout << "Leaving LogInterpolation " << G4endl;
    }
}

//MT: Lock in caller
void G4SPSEneDistribution::ExpInterpolation()
{
  // Interpolation based on Exponential equations
  // Generate equations of line segments
  // y = Ae**-(x/e0) => ln y = -x/e0 + lnA
  // Find area under line segments
  // create normalised, cumulative array Arb_Cum_Area
  G4double Area_seg[1024]; // Stores area under each segment
  G4double sum = 0., Arb_x[1024], Arb_y[1024], Arb_Cum_Area[1024];
  G4int i, count;
  G4int maxi = ArbEnergyH.GetVectorLength();
  for (i = 0; i < maxi; i++)
    {
    Arb_x[i] = ArbEnergyH.GetLowEdgeEnergy(size_t(i));
    Arb_y[i] = ArbEnergyH(size_t(i));
  }
  // Points are now in x,y arrays. If the spectrum is integral it has to be
  // made differential and if momentum it has to be made energy.
  if (DiffSpec == false)
    {
    // Converts integral point-wise spectra to Differential
    for (count = 0; count < maxi - 1; count++)
        {
      Arb_y[count] = (Arb_y[count] - Arb_y[count + 1])
          / (Arb_x[count + 1] - Arb_x[count]);
    }
    maxi--;
  }
  //
  if (EnergySpec == false)
    {
    // change currently stored values (emin etc) which are actually momenta
    // to energies.
        G4ParticleDefinition* pdef = threadLocalData.Get().particle_definition;
    if (pdef == NULL)
        {
            G4Exception("G4SPSEneDistribution::ExpInterpolation",
                        "Event0302",FatalException,
                        "Error: particle not defined");
        }
    else
        {
      // Apply Energy**2 = p**2c**2 + m0**2c**4
      // p should be entered as E/c i.e. without the division by c
      // being done - energy equivalent.
      G4double mass = pdef->GetPDGMass();
      // convert point to energy unit and its value to per energy unit
      G4double total_energy;
      for (count = 0; count < maxi; count++)
            {
        total_energy = std::sqrt((Arb_x[count] * Arb_x[count]) + (mass * mass)); // total energy
        Arb_y[count] = Arb_y[count] * Arb_x[count] / total_energy;
        Arb_x[count] = total_energy - mass; // kinetic energy
      }
    }
  }
  //
  i = 1;
    
    //AG: Should be first use...
    if ( Arb_ezero ) { delete[] Arb_ezero; Arb_ezero = 0; }
    if ( Arb_Const ) { delete[] Arb_Const; Arb_Const = 0; }
    Arb_ezero = new G4double [1024];
    Arb_Const = new G4double [1024];
    Arb_ezero_flag = true;
    
  Arb_ezero[0] = 0.;
  Arb_Const[0] = 0.;
  Area_seg[0] = 0.;
  Arb_Cum_Area[0] = 0.;
  while (i < maxi)
    {
    G4double test = std::log(Arb_y[i]) - std::log(Arb_y[i - 1]);
    if (test > 0. || test < 0.)
        {
      Arb_ezero[i] = -(Arb_x[i] - Arb_x[i - 1]) / (std::log(Arb_y[i]) - std::log(Arb_y[i - 1]));
      Arb_Const[i] = Arb_y[i] / (std::exp(-Arb_x[i] / Arb_ezero[i]));
      Area_seg[i] = -(Arb_Const[i] * Arb_ezero[i]) * (std::exp(-Arb_x[i] / Arb_ezero[i]) - std::exp(-Arb_x[i - 1] / Arb_ezero[i]));
    }
        else
        {
            G4Exception("G4SPSEneDistribution::ExpInterpolation",
                        "Event0302",JustWarning,
                        "Flat line segment: problem, setting to zero parameters.");
      G4cout << "Flat line segment: problem" << G4endl;
      Arb_ezero[i] = 0.;
      Arb_Const[i] = 0.;
      Area_seg[i] = 0.;
    }
    sum = sum + Area_seg[i];
    Arb_Cum_Area[i] = Arb_Cum_Area[i - 1] + Area_seg[i];
    if (verbosityLevel == 2)
        {
      G4cout << Arb_ezero[i] << Arb_Const[i] << Area_seg[i] << G4endl;
        }
    i++;
  }

  i = 0;
  while (i < maxi)
    {
    Arb_Cum_Area[i] = Arb_Cum_Area[i] / sum;
    IPDFArbEnergyH.InsertValues(Arb_x[i], Arb_Cum_Area[i]);
    i++;
  }

  // now scale the ArbEnergyH, needed by Probability()
  ArbEnergyH.ScaleVector(1., 1./sum);

  if (verbosityLevel >= 1)
    {
    G4cout << "Leaving ExpInterpolation " << G4endl;
    }
}

//MT: Lock in caller
void G4SPSEneDistribution::SplineInterpolation()
{
  // Interpolation using Splines.
  // Create Normalised arrays, make x 0->1 and y hold
  // the function (Energy)
        // 
        // Current method based on the above will not work in all cases. 
        // new method is implemented below.
  
  G4double sum, Arb_x[1024], Arb_y[1024], Arb_Cum_Area[1024];
  G4int i, count;

  G4int maxi = ArbEnergyH.GetVectorLength();
  for (i = 0; i < maxi; i++) {
    Arb_x[i] = ArbEnergyH.GetLowEdgeEnergy(size_t(i));
    Arb_y[i] = ArbEnergyH(size_t(i));
  }
  // Points are now in x,y arrays. If the spectrum is integral it has to be
  // made differential and if momentum it has to be made energy.
  if (DiffSpec == false) {
    // Converts integral point-wise spectra to Differential
    for (count = 0; count < maxi - 1; count++)
        {
      Arb_y[count] = (Arb_y[count] - Arb_y[count + 1]) / (Arb_x[count + 1] - Arb_x[count]);
    }
    maxi--;
  }
  //
  if (EnergySpec == false) {
    // change currently stored values (emin etc) which are actually momenta
    // to energies.
        G4ParticleDefinition* pdef = threadLocalData.Get().particle_definition;
    if (pdef == NULL)
                    G4Exception("G4SPSEneDistribution::SplineInterpolation",
                                "Event0302",FatalException,
              "Error: particle not defined");
    else {
      // Apply Energy**2 = p**2c**2 + m0**2c**4
      // p should be entered as E/c i.e. without the division by c
      // being done - energy equivalent.
      G4double mass = pdef->GetPDGMass();
      // convert point to energy unit and its value to per energy unit
      G4double total_energy;
      for (count = 0; count < maxi; count++) {
        total_energy = std::sqrt((Arb_x[count] * Arb_x[count]) + (mass
            * mass)); // total energy

        Arb_y[count] = Arb_y[count] * Arb_x[count] / total_energy;
        Arb_x[count] = total_energy - mass; // kinetic energy
      }
    }
  }

  //
  i = 1;
  Arb_Cum_Area[0] = 0.;
  sum = 0.;
  Splinetemp = new G4DataInterpolation(Arb_x, Arb_y, maxi, 0., 0.);
  G4double ei[101],prob[101];
    for ( std::vector<G4DataInterpolation*>::iterator it = SplineInt.begin() ; it!=SplineInt.end() ; ++it)
    {
        delete *it;
        *it = 0;
    }
    SplineInt.clear();
    SplineInt.resize(1024,NULL);
  while (i < maxi) {
    // 100 step per segment for the integration of area
    G4double de = (Arb_x[i] - Arb_x[i - 1])/100.;
    G4double area = 0.;

    for (count = 0; count < 101; count++) {
      ei[count] = Arb_x[i - 1] + de*count ;
      prob[count] =  Splinetemp->CubicSplineInterpolation(ei[count]);
      if (prob[count] < 0.) { 
              G4ExceptionDescription ED;
        ED << "Warning: G4DataInterpolation returns value < 0  " << prob[count] <<" "<<ei[count]<< G4endl;
              G4Exception("G4SPSEneDistribution::SplineInterpolation","Event0303",
              FatalException,ED);
      }
      area += prob[count]*de;
    }
    Arb_Cum_Area[i] = Arb_Cum_Area[i - 1] + area;
    sum += area; 

    prob[0] = prob[0]/(area/de);
    for (count = 1; count < 100; count++)
      prob[count] = prob[count-1] + prob[count]/(area/de);

    SplineInt[i]=new G4DataInterpolation(prob, ei, 101, 0., 0.);
    // note i start from 1!
    i++;
  }
  i = 0;
  while (i < maxi) {
    Arb_Cum_Area[i] = Arb_Cum_Area[i] / sum; // normalisation
    IPDFArbEnergyH.InsertValues(Arb_x[i], Arb_Cum_Area[i]);
    i++;
  }
  // now scale the ArbEnergyH, needed by Probability()
  ArbEnergyH.ScaleVector(1., 1./sum);

  if (verbosityLevel > 0)
    G4cout << "Leaving SplineInterpolation " << G4endl;
}

void G4SPSEneDistribution::GenerateMonoEnergetic() {
  // Method to generate MonoEnergetic particles.
    threadLocalData.Get().particle_energy = MonoEnergy;
}

void G4SPSEneDistribution::GenerateGaussEnergies() {
  // Method to generate Gaussian particles.
  G4double ene = G4RandGauss::shoot(MonoEnergy,SE);
  if (ene < 0) ene = 0.;
    threadLocalData.Get().particle_energy = ene;
}

void G4SPSEneDistribution::GenerateLinearEnergies(G4bool bArb = false) {
  G4double rndm;
    threadLocal_t& params = threadLocalData.Get();
  G4double emaxsq = std::pow(params.Emax, 2.); //Emax squared
  G4double eminsq = std::pow(params.Emin, 2.); //Emin squared
  G4double intersq = std::pow(params.cept, 2.); //cept squared

  if (bArb)
    rndm = G4UniformRand();
  else
    rndm = eneRndm->GenRandEnergy();

  G4double bracket = ((params.grad / 2.) * (emaxsq - eminsq) + params.cept * (params.Emax - params.Emin));
  bracket = bracket * rndm;
  bracket = bracket + (params.grad / 2.) * eminsq + params.cept * params.Emin;
  // Now have a quad of form m/2 E**2 + cE - bracket = 0
  bracket = -bracket;
  //  G4cout << "BRACKET" << bracket << G4endl;
  if (params.grad != 0.)
    {
    G4double sqbrack = (intersq - 4 * (params.grad / 2.) * (bracket));
    //      G4cout << "SQBRACK" << sqbrack << G4endl;
    sqbrack = std::sqrt(sqbrack);
    G4double root1 = -params.cept + sqbrack;
    root1 = root1 / (2. * (params.grad / 2.));

    G4double root2 = -params.cept - sqbrack;
    root2 = root2 / (2. * (params.grad / 2.));

    //      G4cout << root1 << " roots " << root2 << G4endl;

    if (root1 > params.Emin && root1 < params.Emax)
        {
      params.particle_energy = root1;
        }
    if (root2 > params.Emin && root2 < params.Emax)
        {
      params.particle_energy = root2;
        }
  }
    else if (params.grad == 0.)
    {
    // have equation of form cE - bracket =0
    params.particle_energy = bracket / params.cept;
    }

  if (params.particle_energy < 0.)
    {
    params.particle_energy = -params.particle_energy;
    }

  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << params.particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GeneratePowEnergies(G4bool bArb = false)
{
  // Method to generate particle energies distributed as
  // a power-law

  G4double rndm;
  G4double emina, emaxa;
    
    threadLocal_t& params = threadLocalData.Get();
    
  emina = std::pow(params.Emin, params.alpha + 1);
  emaxa = std::pow(params.Emax, params.alpha + 1);

  if (bArb)
    {
    rndm = G4UniformRand();
    }
  else
    {
    rndm = eneRndm->GenRandEnergy();
    }

  if (params.alpha != -1.)
    {
    G4double ene = ((rndm * (emaxa - emina)) + emina);
    ene = std::pow(ene, (1. / (params.alpha + 1.)));
        params.particle_energy = ene;
  }
    else
    {
    G4double ene = (std::log(params.Emin) + rndm * (std::log(params.Emax) - std::log(params.Emin)));
    params.particle_energy = std::exp(ene);
  }
  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << params.particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GenerateCPowEnergies()
{
  // Method to generate particle energies distributed in
  // cutoff power-law distribution

  // CP_x holds Energies, and CPHist holds the cumulative histo.
  // binary search to find correct bin then lin interpolation.
  // Use the earlier defined histogram + RandGeneral method to generate
  // random numbers following the histos distribution.
  G4double rndm;
  G4int nabove, nbelow = 0, middle;
  nabove = 10001;
  rndm = eneRndm->GenRandEnergy();
    G4AutoLock l(&mutex);
    G4bool done = CPhistCalcd;
    l.unlock();
    if(!done)
    {
        Calculate(); //This is has a lock inside, risk is to do it twice
        l.lock();
        CPhistCalcd = true;
        l.unlock();
    }

  // Binary search to find bin that rndm is in
  while (nabove - nbelow > 1)
    {
    middle = (nabove + nbelow) / 2;
    if (rndm == CPHist->at(middle))
        {
      break;
        }
    if (rndm < CPHist->at(middle))
        {
      nabove = middle;
        }
    else
        {
      nbelow = middle;
        }
  }

  // Now interpolate in that bin to find the correct output value.
  G4double x1, x2, y1, y2, t, q;
  x1 = CP_x->at(nbelow);
    if(nbelow+1 == static_cast<G4int>(CP_x->size()))
    {
        x2 = CP_x->back();
    }
    else
    {
        x2 = CP_x->at(nbelow + 1);
    }
  y1 = CPHist->at(nbelow);
    if(nbelow+1 == static_cast<G4int>(CPHist->size()))
    {
        G4cout << CPHist->back() << G4endl;
        y2 = CPHist->back();
    }
    else
    {
        y2 = CPHist->at(nbelow + 1);
    }
  t = (y2 - y1) / (x2 - x1);
  q = y1 - t * x1;

  threadLocalData.Get().particle_energy = (rndm - q) / t;

  if (verbosityLevel >= 1) {
    G4cout << "Energy is " << threadLocalData.Get().particle_energy << G4endl;
  }
}

void G4SPSEneDistribution::GenerateBiasPowEnergies()//G4double& ene,G4double& wweight)
{
  // Method to generate particle energies distributed as
  // in biased power-law and calculate its weight
    
    threadLocal_t& params = threadLocalData.Get();
    
    G4double rndm;
    G4double emina, emaxa, emin, emax;

    G4double normal = 1.;

    emin = params.Emin;
    emax = params.Emax;
    //  if (EnergyDisType == "Arb") {
    //  emin = ArbEmin;
    //  emax = ArbEmax;
    //}

    rndm = eneRndm->GenRandEnergy();

    if (biasalpha != -1.)
    {
        emina = std::pow(emin, biasalpha + 1);
        emaxa = std::pow(emax, biasalpha + 1);
        G4double ee = ((rndm * (emaxa - emina)) + emina);
        params.particle_energy = std::pow(ee, (1. / (biasalpha + 1.)));
        normal = 1./(1+biasalpha) * (emaxa - emina);
    }
    else
    {
        G4double ee = (std::log(emin) + rndm * (std::log(emax) - std::log(emin)));
        params.particle_energy = std::exp(ee);
        normal = std::log(emax) - std::log(emin) ;
    }
    params.weight = GetProbability(params.particle_energy)
                      / (std::pow(params.particle_energy,biasalpha)/normal);

    if (verbosityLevel >= 1)
    {
        G4cout << "Energy is " << params.particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GenerateExpEnergies(G4bool bArb = false)
{
  // Method to generate particle energies distributed according
  // to an exponential curve.
  G4double rndm;

  if (bArb)
    {
    rndm = G4UniformRand();
    }
  else
    {
    rndm = eneRndm->GenRandEnergy();
    }

    threadLocal_t& params = threadLocalData.Get();
  params.particle_energy = -params.Ezero * (std::log(rndm * (std::exp(-params.Emax / params.Ezero) - std::exp(-params.Emin / params.Ezero)) + std::exp(-params.Emin / params.Ezero)));
  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << params.particle_energy  << G4endl;
    }
}

void G4SPSEneDistribution::GenerateBremEnergies()
{
  // Method to generate particle energies distributed according
  // to a Bremstrahlung equation of
  // form I = const*((kT)**1/2)*E*(e**(-E/kT))

  G4double rndm;
  rndm = eneRndm->GenRandEnergy();
  G4double expmax, expmin, k;
    
  k = 8.6181e-11; // Boltzmann's const in MeV/K
  G4double ksq = std::pow(k, 2.); // k squared
  G4double Tsq = std::pow(Temp, 2.); // Temp squared

    threadLocal_t& params = threadLocalData.Get();

  expmax = std::exp(-params.Emax / (k * Temp));
  expmin = std::exp(-params.Emin / (k * Temp));

  // If either expmax or expmin are zero then this will cause problems
  // Most probably this will be because T is too low or E is too high

  if (expmax == 0.)
    {
        G4Exception("G4SPSEneDistribution::GenerateBremEnergies",
                    "Event0302",FatalException,
              "*****EXPMAX=0. Choose different E's or Temp");
    }
  if (expmin == 0.)
    {
        G4Exception("G4SPSEneDistribution::GenerateBremEnergies",
                    "Event0302",FatalException,
              "*****EXPMIN=0. Choose different E's or Temp");
    }

  G4double tempvar = rndm * ((-k) * Temp * (params.Emax * expmax - params.Emin * expmin) - (ksq * Tsq * (expmax - expmin)));

  G4double bigc = (tempvar - k * Temp * params.Emin * expmin - ksq * Tsq * expmin) / (-k * Temp);

  // This gives an equation of form: Ee(-E/kT) + kTe(-E/kT) - C =0
  // Solve this iteratively, step from Emin to Emax in 1000 steps
  // and take the best solution.

  G4double erange = params.Emax - params.Emin;
  G4double steps = erange / 1000.;
  G4int i;
  G4double etest, diff, err;

  err = 100000.;

  for (i = 1; i < 1000; i++)
    {
    etest = params.Emin + (i - 1) * steps;

    diff = etest * (std::exp(-etest / (k * Temp))) + k * Temp * (std::exp(-etest / (k * Temp))) - bigc;

    if (diff < 0.)
        {
      diff = -diff;
        }

    if (diff < err)
        {
      err = diff;
      params.particle_energy = etest;
    }
  }
  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << params.particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GenerateBbodyEnergies()
{
  // BBody_x holds Energies, and BBHist holds the cumulative histo.
  // binary search to find correct bin then lin interpolation.
  // Use the earlier defined histogram + RandGeneral method to generate
  // random numbers following the histos distribution.
  G4double rndm;
  G4int nabove, nbelow = 0, middle;
  nabove = 10001;
  rndm = eneRndm->GenRandEnergy();
    G4AutoLock l(&mutex);
    G4bool done = BBhistCalcd;
    l.unlock();
    if(!done)
    {
        Calculate(); //This is has a lock inside, risk is to do it twice
        l.lock();
        BBhistCalcd = true;
        l.unlock();
    }

  // Binary search to find bin that rndm is in
  while (nabove - nbelow > 1)
    {
    middle = (nabove + nbelow) / 2;
    if (rndm == BBHist->at(middle))
        {
      break;
        }
    if (rndm < BBHist->at(middle))
        {
      nabove = middle;
        }
    else
        {
      nbelow = middle;
        }
  }

  // Now interpolate in that bin to find the correct output value.
  G4double x1, x2, y1, y2, t, q;
  x1 = Bbody_x->at(nbelow);
    if(nbelow+1 == static_cast<G4int>(Bbody_x->size()))
    {
        x2 = Bbody_x->back();
    }
    else
    {
        x2 = Bbody_x->at(nbelow + 1);
    }
  y1 = BBHist->at(nbelow);
    if(nbelow+1 == static_cast<G4int>(BBHist->size()))
    {
        G4cout << BBHist->back() << G4endl;
        y2 = BBHist->back();
    }
    else
    {
        y2 = BBHist->at(nbelow + 1);
    }
  t = (y2 - y1) / (x2 - x1);
  q = y1 - t * x1;

  threadLocalData.Get().particle_energy = (rndm - q) / t;

  if (verbosityLevel >= 1) {
    G4cout << "Energy is " << threadLocalData.Get().particle_energy << G4endl;
  }
}

void G4SPSEneDistribution::GenerateCdgEnergies() {
  // Gen random numbers, compare with values in cumhist
  // to find appropriate part of spectrum and then
  // generate energy in the usual inversion way.
  //  G4double pfact[2] = {8.5, 112};
  // G4double spind[2] = {1.4, 2.3};
  // G4double ene_line[3] = {1., 18., 1E6};
  G4double rndm, rndm2;
  G4double ene_line[3]={0,0,0};
  G4double omalpha[2]={0,0};
    threadLocal_t& params = threadLocalData.Get();
  if (params.Emin < 18 * keV && params.Emax < 18 * keV)
    {
    omalpha[0] = 1. - 1.4;
    ene_line[0] = params.Emin;
    ene_line[1] = params.Emax;
  }
  if (params.Emin < 18 * keV && params.Emax > 18 * keV)
    {
    omalpha[0] = 1. - 1.4;
    omalpha[1] = 1. - 2.3;
    ene_line[0] = params.Emin;
    ene_line[1] = 18. * keV;
    ene_line[2] = params.Emax;
  }
  if (params.Emin > 18 * keV)
    {
    omalpha[0] = 1. - 2.3;
    ene_line[0] = params.Emin;
    ene_line[1] = params.Emax;
  }
  rndm = eneRndm->GenRandEnergy();
  rndm2 = eneRndm->GenRandEnergy();

  G4int i = 0;
  while (rndm >= CDGhist[i])
    {
    i++;
  }
  // Generate final energy.
  G4double ene = (std::pow(ene_line[i - 1], omalpha[i - 1]) + (std::pow(ene_line[i], omalpha[i - 1]) - std::pow(ene_line[i - 1], omalpha[i- 1])) * rndm2);
  params.particle_energy = std::pow(ene, (1. / omalpha[i - 1]));

  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << params.particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GenUserHistEnergies()
{
  // Histograms are DIFFERENTIAL.
  //  G4cout << "In GenUserHistEnergies " << G4endl;
    G4AutoLock l(&mutex);
  if (IPDFEnergyExist == false)
    {
    G4int ii;
    G4int maxbin = G4int(UDefEnergyH.GetVectorLength());
    G4double bins[1024], vals[1024], sum;
    for ( ii = 0 ; ii<1024 ; ++ii ) { bins[ii]=0; vals[ii]=0; }
    sum = 0.;

    if ((EnergySpec == false) && (threadLocalData.Get().particle_definition == NULL))
        {
            G4Exception("G4SPSEneDistribution::GenUserHistEnergies",
                        "Event0302",FatalException,
                        "Error: particle definition is NULL");
        }

    if (maxbin > 1024)
        {
            G4Exception("G4SPSEneDistribution::GenUserHistEnergies",
                        "Event0302",JustWarning,"Maxbin>1024\n Setting maxbin to 1024, other bins are lost");
            maxbin = 1024;
    }

    if (DiffSpec == false)
        {
      G4cout << "Histograms are Differential!!! " << G4endl;
        }
    else
        {
      bins[0] = UDefEnergyH.GetLowEdgeEnergy(size_t(0));
      vals[0] = UDefEnergyH(size_t(0));
      sum = vals[0];
      for (ii = 1; ii < maxbin; ii++)
            {
        bins[ii] = UDefEnergyH.GetLowEdgeEnergy(size_t(ii));
        vals[ii] = UDefEnergyH(size_t(ii)) + vals[ii - 1];
        sum = sum + UDefEnergyH(size_t(ii));
      }
    }

    if (EnergySpec == false)
        {
      G4double mass = threadLocalData.Get().particle_definition->GetPDGMass();
      // multiply the function (vals) up by the bin width
      // to make the function counts/s (i.e. get rid of momentum
      // dependence).
      for (ii = 1; ii < maxbin; ii++)
            {
        vals[ii] = vals[ii] * (bins[ii] - bins[ii - 1]);
      }
      // Put energy bins into new histo, plus divide by energy bin width
      // to make evals counts/s/energy
      for (ii = 0; ii < maxbin; ii++)
            {
        bins[ii] = std::sqrt((bins[ii] * bins[ii]) + (mass * mass))- mass; //kinetic energy
      }
      for (ii = 1; ii < maxbin; ii++)
            {
        vals[ii] = vals[ii] / (bins[ii] - bins[ii - 1]);
      }
      sum = vals[maxbin - 1];
      vals[0] = 0.;
    }
    for (ii = 0; ii < maxbin; ii++)
        {
      vals[ii] = vals[ii] / sum;
      IPDFEnergyH.InsertValues(bins[ii], vals[ii]);
    }

    // Make IPDFEnergyExist = true
    IPDFEnergyExist = true;
    if (verbosityLevel > 1)
        {
      IPDFEnergyH.DumpValues();
        }
  }
    l.unlock();
    
  // IPDF has been create so carry on
  G4double rndm = eneRndm->GenRandEnergy();
  threadLocalData.Get().particle_energy= IPDFEnergyH.GetEnergy(rndm);

  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << particle_energy << G4endl;
    }
}

void G4SPSEneDistribution::GenArbPointEnergies()
{
  if (verbosityLevel > 0)
    {
    G4cout << "In GenArbPointEnergies" << G4endl;
    }
  G4double rndm;
  rndm = eneRndm->GenRandEnergy();
  //      IPDFArbEnergyH.DumpValues();
  // Find the Bin
  // have x, y, no of points, and cumulative area distribution
  G4int nabove, nbelow = 0, middle;
  nabove = IPDFArbEnergyH.GetVectorLength();
  //      G4cout << nabove << G4endl;
  // Binary search to find bin that rndm is in
  while (nabove - nbelow > 1)
    {
        middle = (nabove + nbelow) / 2;
        if (rndm == IPDFArbEnergyH(size_t(middle)))
        {
            break;
        }
        if (rndm < IPDFArbEnergyH(size_t(middle)))
        {
            nabove = middle;
        }
        else
        {
            nbelow = middle;
        }
  }
    threadLocal_t& params = threadLocalData.Get();
  if (IntType == "Lin")
    {
        //Update thread-local copy of parameters
        params.Emax = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow + 1));
        params.Emin = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow));
        params.grad = Arb_grad[nbelow + 1];
        params.cept = Arb_cept[nbelow + 1];
        //    G4cout << rndm << " " << Emax << " " << Emin << " " << grad << " " << cept << G4endl;
        GenerateLinearEnergies(true);
  }
    else if (IntType == "Log")
    {
        params.Emax = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow + 1));
        params.Emin = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow));
        params.alpha = Arb_alpha[nbelow + 1];
        //    G4cout << rndm << " " << Emax << " " << Emin << " " << alpha << G4endl;
        GeneratePowEnergies(true);
  }
    else if (IntType == "Exp")
    {
        params.Emax = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow + 1));
        params.Emin = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow));
        params.Ezero = Arb_ezero[nbelow + 1];
        //    G4cout << rndm << " " << Emax << " " << Emin << " " << Ezero << G4endl;
        GenerateExpEnergies(true);
  }
    else if (IntType == "Spline")
    {
        params.Emax = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow + 1));
        params.Emin = IPDFArbEnergyH.GetLowEdgeEnergy(size_t(nbelow));
        params.particle_energy = -1e100;
        rndm = eneRndm->GenRandEnergy();
        while (params.particle_energy < params.Emin || params.particle_energy > params.Emax)
        {
            params.particle_energy = SplineInt[nbelow+1]->CubicSplineInterpolation(rndm);
            rndm = eneRndm->GenRandEnergy();
        }
        if (verbosityLevel >= 1)
        {
            G4cout << "Energy is " << params.particle_energy << G4endl;
        }
  }
    else
    {
        G4Exception("G4SPSEneDistribution::GenArbPointEnergies","Event0302",
                    FatalException,"Error: IntType unknown type");
    }
}

void G4SPSEneDistribution::GenEpnHistEnergies() {
  //  G4cout << "In GenEpnHistEnergies " << Epnflag << G4endl;

  // Firstly convert to energy if not already done.
    G4AutoLock l(&mutex);
  if (Epnflag == true)
  // epnflag = true means spectrum is epn, false means e.
  {
    // convert to energy by multiplying by A number
    ConvertEPNToEnergy();
    // EpnEnergyH will be replace by UDefEnergyH.
    //      UDefEnergyH.DumpValues();
  }
  if (IPDFEnergyExist == false)
    {
    // IPDF has not been created, so create it
    G4double bins[1024], vals[1024], sum;
    G4int ii;
    G4int maxbin = G4int(UDefEnergyH.GetVectorLength());
    bins[0] = UDefEnergyH.GetLowEdgeEnergy(size_t(0));
    vals[0] = UDefEnergyH(size_t(0));
    sum = vals[0];
    for (ii = 1; ii < maxbin; ii++)
        {
      bins[ii] = UDefEnergyH.GetLowEdgeEnergy(size_t(ii));
      vals[ii] = UDefEnergyH(size_t(ii)) + vals[ii - 1];
      sum = sum + UDefEnergyH(size_t(ii));
    }

        l.lock();
    for (ii = 0; ii < maxbin; ii++)
        {
      vals[ii] = vals[ii] / sum;
      IPDFEnergyH.InsertValues(bins[ii], vals[ii]);
    }
    // Make IPDFEpnExist = true
    IPDFEnergyExist = true;
       
  }
    l.unlock();
  //  IPDFEnergyH.DumpValues();
  // IPDF has been create so carry on
  G4double rndm = eneRndm->GenRandEnergy();
  threadLocalData.Get().particle_energy = IPDFEnergyH.GetEnergy(rndm);

  if (verbosityLevel >= 1)
    {
    G4cout << "Energy is " << threadLocalData.Get().particle_energy << G4endl;
    }
}

//MT: lock in caller
void G4SPSEneDistribution::ConvertEPNToEnergy()
{
  // Use this before particle generation to convert  the
  // currently stored histogram from energy/nucleon
  // to energy.
  //  G4cout << "In ConvertEpntoEnergy " << G4endl;
    threadLocal_t& params = threadLocalData.Get();
  if (params.particle_definition == NULL)
    {
    G4cout << "Error: particle not defined" << G4endl;
    }
  else
    {
    // Need to multiply histogram by the number of nucleons.
    // Baryon Number looks to hold the no. of nucleons.
    G4int Bary = params.particle_definition->GetBaryonNumber();
    //      G4cout << "Baryon No. " << Bary << G4endl;
    // Change values in histogram, Read it out, delete it, re-create it
    G4int count, maxcount;
    maxcount = G4int(EpnEnergyH.GetVectorLength());
    //      G4cout << maxcount << G4endl;
    G4double ebins[1024], evals[1024];
    if (maxcount > 1024)
        {
            G4Exception("G4SPSEneDistribution::ConvertEPNToEnergy()","gps001", JustWarning,
                        "Histogram contains more than 1024 bins!\nThose above 1024 will be ignored");
      maxcount = 1024;
    }
    if (maxcount < 1)
        {
            G4Exception("G4SPSEneDistribution::ConvertEPNToEnergy()","gps001", FatalException,"Histogram contains less than 1 bin!\nRedefine the histogram");
      return;
    }
    for (count = 0; count < maxcount; count++)
        {
      // Read out
      ebins[count] = EpnEnergyH.GetLowEdgeEnergy(size_t(count));
      evals[count] = EpnEnergyH(size_t(count));
    }

    // Multiply the channels by the nucleon number to give energies
    for (count = 0; count < maxcount; count++)
        {
      ebins[count] = ebins[count] * Bary;
    }

    // Set Emin and Emax
    params.Emin = ebins[0];
    if (maxcount > 1)
        {
      params.Emax = ebins[maxcount - 1];
        }
    else
        {
      params.Emax = ebins[0];
        }
    // Put energy bins into new histogram - UDefEnergyH.
    for (count = 0; count < maxcount; count++)
        {
      UDefEnergyH.InsertValues(ebins[count], evals[count]);
    }
    Epnflag = false; //so that you dont repeat this method.
  }
}

//
void G4SPSEneDistribution::ReSetHist(G4String atype)
{
    G4AutoLock l(&mutex);
  if (atype == "energy")
    {
    UDefEnergyH = IPDFEnergyH = ZeroPhysVector;
    IPDFEnergyExist = false;
    Emin = 0.;
    Emax = 1e30;
  }
    else if (atype == "arb")
    {
    ArbEnergyH = IPDFArbEnergyH = ZeroPhysVector;
    IPDFArbExist = false;
  }
    else if (atype == "epn")
    {
    UDefEnergyH = IPDFEnergyH = ZeroPhysVector;
    IPDFEnergyExist = false;
    EpnEnergyH = ZeroPhysVector;
  }
    else
    {
    G4cout << "Error, histtype not accepted " << G4endl;
  }
}

G4double G4SPSEneDistribution::GenerateOne(G4ParticleDefinition* a)
{
    //Copy global shared status to thread-local one
    threadLocal_t& params = threadLocalData.Get();
    params.particle_definition=a;
    params.particle_energy=-1;
    params.Emax = Emax;
    params.Emin = Emin;
    params.alpha = alpha;
    params.Ezero = Ezero;
    params.grad = grad;
    params.cept = cept;
    params.weight = weight;
    //particle_energy = -1.;
    while ((EnergyDisType == "Arb") ? (params.particle_energy < ArbEmin || params.particle_energy > ArbEmax) : (params.particle_energy < params.Emin|| params.particle_energy > params.Emax))
    {
        if (Biased)
        {
            GenerateBiasPowEnergies();
        }
        else
        {
      if (EnergyDisType == "Mono")
            {
        GenerateMonoEnergetic();
            }
      else if (EnergyDisType == "Lin")
            {
        GenerateLinearEnergies(false);
            }
      else if (EnergyDisType == "Pow")
            {
        GeneratePowEnergies(false);
            }
      else if (EnergyDisType == "CPow")
            {
        GenerateCPowEnergies();
            }
      else if (EnergyDisType == "Exp")
            {
        GenerateExpEnergies(false);
            }
      else if (EnergyDisType == "Gauss")
            {
        GenerateGaussEnergies();
            }
      else if (EnergyDisType == "Brem")
            {
        GenerateBremEnergies();
            }
      else if (EnergyDisType == "Bbody")
            {
        GenerateBbodyEnergies();
            }
      else if (EnergyDisType == "Cdg")
            {
        GenerateCdgEnergies();
            }
      else if (EnergyDisType == "User")
            {
        GenUserHistEnergies();
            }
      else if (EnergyDisType == "Arb")
            {
        GenArbPointEnergies();
            }
      else if (EnergyDisType == "Epn")
            {
        GenEpnHistEnergies();
            }
      else
            {
        G4cout << "Error: EnergyDisType has unusual value" << G4endl;
            }
    }
  }
  return params.particle_energy;
}

G4double G4SPSEneDistribution::GetProbability(G4double ene)
{
    G4double prob = 1.;

    threadLocal_t& params = threadLocalData.Get();
    if (EnergyDisType == "Lin")
    {
        if (prob_norm == 1.)
        {
            prob_norm = 0.5*params.grad*params.Emax*params.Emax + params.cept*params.Emax - 0.5*params.grad*params.Emin*params.Emin - params.cept*params.Emin;
        }
        prob = params.cept + params.grad * ene;
        prob /= prob_norm;
    }
    else if (EnergyDisType == "Pow")
    {
        if (prob_norm == 1.)
        {
            if (alpha != -1.)
            {
                G4double emina = std::pow(params.Emin, params.alpha + 1);
                G4double emaxa = std::pow(params.Emax, params.alpha + 1);
                prob_norm = 1./(1.+alpha) * (emaxa - emina);
            }
            else
            {
                prob_norm = std::log(params.Emax) - std::log(params.Emin) ;
            }
        }
        prob = std::pow(ene, params.alpha)/prob_norm;
    }
    else if (EnergyDisType == "Exp")
    {
        if (prob_norm == 1.)
        {
            prob_norm = -params.Ezero*(std::exp(-params.Emax/params.Ezero) - std::exp(params.Emin/params.Ezero));
        }  
        prob = std::exp(-ene / params.Ezero);
        prob /= prob_norm;
    }
    else if (EnergyDisType == "Arb")
    {
        prob = ArbEnergyH.Value(ene);
        //  prob = ArbEInt->CubicSplineInterpolation(ene);
        //G4double deltaY;
        //prob = ArbEInt->PolynomInterpolation(ene, deltaY);
        if (prob <= 0.)
        {
            //G4cout << " Warning:G4SPSEneDistribution::GetProbability: prob<= 0. "<<prob <<" "<<ene << " " <<deltaY<< G4endl;
            G4cout << " Warning:G4SPSEneDistribution::GetProbability: prob<= 0. "<<prob <<" "<<ene << G4endl;
            prob = 1e-30;
        }
        // already normalised
    }
  else
    {
    G4cout << "Error: EnergyDisType not supported" << G4endl;
    }
       
  return prob;
}