ThermalNeutronBk2BkExpConvPVoigt.h

#ifndef MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPVOIGT_H_
#define MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPVOIGT_H_

#include "MantidKernel/System.h"
#include "MantidAPI/IPowderDiffPeakFunction.h"

#include <complex>

namespace Mantid {
namespace CurveFitting {
namespace Functions {

/** ThermalNeutronBk2BkExpConvPVoigt :
    Back-to-back exponential convoluted with pseudo Voigt for thermal neutron
  and epithermal neutron TOF

    It will involve the calculation from peak's miller indices

  Copyright &copy; 2012 ISIS Rutherford Appleton Laboratory, NScD Oak Ridge
  National Laboratory & European Spallation Source

  This file is part of Mantid.

  Mantid 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.

  Mantid 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 this program.  If not, see <http://www.gnu.org/licenses/>.

  File change history is stored at: <https://github.com/mantidproject/mantid>
  Code Documentation is available at: <http://doxygen.mantidproject.org>
*/

class DLLExport ThermalNeutronBk2BkExpConvPVoigt
    : public API::IPowderDiffPeakFunction {
public:
  ThermalNeutronBk2BkExpConvPVoigt();

  /// Overwrite IFunction base class methods
  std::string name() const override {
    return "ThermalNeutronBk2BkExpConvPVoigt";
  }
  const std::string category() const override { return "General"; }

  /// Overwrite IPeakFunction base class methods
  /*
  virtual double centre()const;

  virtual double fwhm()const;
  virtual void setHeight(const double h);
  virtual void setPeakRadius(const int& r);
  */

  //--------------- ThermalNeutron peak function special
  //---------------------------------------
  /// Set Miller Indicies
  // virtual void setMillerIndex(int h, int k, int l);

  /// Get Miller Index from this peak
  // virtual void getMillerIndex(int& h, int &k, int &l);

  /// Get peak parameters
  double getPeakParameter(std::string) override;

  /// Calculate peak parameters (alpha, beta, sigma2..)
  void calculateParameters(bool explicitoutput) const override;

  /// Core function to calcualte peak values for whole region
  // void functionLocal(vector<double>& out, const vector<double> &xValues)
  // const;

  /// Set up the flag to show whether (from client) cell parameter value changed
  /*
  void setUnitCellParameterValueChangeFlag(bool changed)
  {
    m_cellParamValueChanged = changed;
  }
  */

  /// Override setting a new value to the i-th parameter
  void setParameter(size_t i, const double &value,
                    bool explicitlySet = true) override;

  /// Override setting a new value to a parameter by name
  void setParameter(const std::string &name, const double &value,
                    bool explicitlySet = true) override;

  /// Set peak's height
  // virtual void setHeight(const double h);
  /// Get peak's height
  // virtual double height()const;

  using IFunction1D::function;
  void function(std::vector<double> &out,
                const std::vector<double> &xValues) const override;

  /// Function you want to fit to.
  void function1D(double *out, const double *xValues,
                  const size_t nData) const override;

private:
  //----- Overwrite IFunction ------------------------------------------------
  /// Fuction local
  void functionLocal(double *out, const double *xValues,
                     const size_t nData) const;
  /// Derivative
  virtual void functionDerivLocal(API::Jacobian *out, const double *xValues,
                                  const size_t nData);
  /// Derivative
  void functionDeriv(const API::FunctionDomain &domain,
                     API::Jacobian &jacobian) override;

  /// Overwrite IFunction base class method, which declare function parameters
  void init() override;

  static int s_peakRadius;

  //--------  Private Functions -----------------------------------
  /// Calcualte H and Eta
  void calHandEta(double sigma2, double gamma, double &H, double &eta) const;

  /// Calculate peak center
  double calPeakCenter() const;

  /// Calculate peak profile I(TOF) = Omega(TOF)
  double calOmega(const double x, const double eta, const double N,
                  const double alpha, const double beta, const double H,
                  const double sigma2, const double invert_sqrt2sigma,
                  const bool explicitoutput = false) const;

  /// Set 2 functions to be hidden from client
  /*
  virtual void setCentre(const double c);
  virtual void setFwhm(const double w);
  */

  //------------------------------------------  Variables
  //--------------------------------------

  /// BackToBackExponential parameters
  mutable double m_Alpha;
  mutable double m_Beta;
  mutable double m_Sigma2;
  mutable double m_Gamma;

  /// FWHM
  // mutable double m_fwhm;

  /// Centre
  // mutable double m_centre;
  // mutable double m_dcentre;

  /// Thermal/Epithermal neutron related
  mutable double m_eta;
  mutable double m_N;

  /// Override setting a new value to the

  //-----------  For Parallelization -----------------------------------------
  ///
  void interruption_point() const;
  /// Set to true to stop execution
  mutable bool m_cancel;
  /// Set if an exception is thrown, and not caught, within a parallel region
  mutable bool m_parallelException;
  /// Flag to show whether the unit cell has been calcualted
  mutable bool m_dspaceCalculated;

  /// Flag to indicate whether there is new parameter value set after
  /// calculating parameters
  // mutable bool m_newValueSet;
};

/// Shared pointer to ThermalNeutronBk2BkExpConvPVoigt peak/function
typedef boost::shared_ptr<ThermalNeutronBk2BkExpConvPVoigt>
    ThermalNeutronBk2BkExpConvPVoigt_sptr;

//--- Public inline function --------------------------------------------------
/** Calculate d = a/sqrt(h**2+k**2+l**2)
inline double calCubicDSpace(double a, int h, int k, int l)
{
    // TODO This function will be refactored in future.
    double d = a/( sqrt(double(h*h)+double(k*k)+double(l*l)) );

    return d;
}
*/

/// Integral for Gamma
// std::complex<double> E1X(std::complex<double> z);

} // namespace Functions
} // namespace CurveFitting
} // namespace Mantid

#endif /* MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPVOIGT_H_ */