Implement peak profile for neutron TOF. Refs #5306.

Code/Mantid/Framework/CurveFitting/CMakeLists.txt

@@ -65,6 +65,7 @@ set ( SRC_FILES
 	src/SteepestDescentMinimizer.cpp
 	src/StretchExp.cpp
 	src/StretchExpMuon.cpp
+	src/ThermalNeutronBk2BkExpConvPV.cpp
 	src/UserFunction.cpp
 	src/UserFunction1D.cpp
 	src/UserFunctionMD.cpp
@@ -146,6 +147,7 @@ set ( INC_FILES
 	inc/MantidCurveFitting/SteepestDescentMinimizer.h
 	inc/MantidCurveFitting/StretchExp.h
 	inc/MantidCurveFitting/StretchExpMuon.h
+	inc/MantidCurveFitting/ThermalNeutronBk2BkExpConvPV.h
 	inc/MantidCurveFitting/UserFunction.h
 	inc/MantidCurveFitting/UserFunction1D.h
 	inc/MantidCurveFitting/UserFunctionMD.h
@@ -208,6 +210,7 @@ set ( TEST_FILES
 	test/StaticKuboToyabeTest.h
 	test/StretchExpMuonTest.h
 	test/StretchExpTest.h
+	test/ThermalNeutronBk2BkExpConvPVTest.h
 	test/UserFunction1DTest.h
 	test/UserFunctionTest.h
 )

Code/Mantid/Framework/CurveFitting/inc/MantidCurveFitting/ThermalNeutronBk2BkExpConvPV.h

@@ -0,0 +1,113 @@
+#ifndef MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPV_H_
+#define MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPV_H_
+
+#include "MantidKernel/System.h"
+#include "MantidAPI/IPeakFunction.h"
+#include "MantidAPI/IFunctionMW.h"
+#include "MantidKernel/Logger.h"
+#include <complex>
+
+namespace Mantid
+{
+namespace CurveFitting
+{
+
+  /** ThermalNeutronBk2BkExpConvPV :
+      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
+
+    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://svn.mantidproject.org/mantid/trunk/Code/Mantid>
+    Code Documentation is available at: <http://doxygen.mantidproject.org>
+  */
+class DLLExport ThermalNeutronBk2BkExpConvPV : virtual public API::IPeakFunction, virtual public API::IFunctionMW
+{
+  public:
+    ThermalNeutronBk2BkExpConvPV();
+    virtual ~ThermalNeutronBk2BkExpConvPV();
+
+    /// overwrite IPeakFunction base class methods
+    virtual double centre()const;
+    virtual double height()const;
+    virtual double fwhm()const;
+
+    virtual void setHeight(const double h);
+
+    /// overwrite IFunction base class methods
+    std::string name()const{return "Bk2BkExpConvPV";}
+    virtual const std::string category() const { return "Peak";}
+
+    /// Set up the range of peak calculation for higher efficiency
+
+    /// Reset FWHM such that FWHM will be recalculated
+    void resetFWHM();
+
+    /// Set Miller Indicies
+    void setMillerIndex(int h, int k, int l);
+
+  protected:
+
+    virtual void functionLocal(double* out, const double* xValues, const size_t nData)const;
+    virtual void functionDerivLocal(API::Jacobian* out, const double* xValues, const size_t nData);
+    virtual void functionDeriv(const API::FunctionDomain& domain, API::Jacobian& jacobian);
+
+    /// overwrite IFunction base class method, which declare function parameters
+    virtual void init();
+
+  private:
+
+    /// Static reference to the logger class
+    static Kernel::Logger& g_log;
+
+    /// Integral for gamma
+    std::complex<double> E1(std::complex<double> z) const;
+
+    /// Calcualte H and Eta
+    void calHandEta(double sigma2, double gamma, double& H, double& eta) const;
+
+    /// Calcualte d-spacing value from Miller Indices for cubic
+    double calCubicDSpace(double a, int h, int k, int l) const;
+
+    /// Calculate peak center
+    double calPeakCenter() const;
+
+    /// Calculate peak profile I(TOF) = Omega(TOF)
+    double calOmega(double x, double eta, double N, double alpha, double beta, double H,
+        double sigma2, double invert_sqrt2sigma) const;
+
+    /*
+     * Set 2 functions to be hidden from client
+     */
+    virtual void setCentre(const double c);
+    virtual void setFwhm(const double w);
+
+    int mH;
+    int mK;
+    int mL;
+
+    bool mHKLSet;
+
+};
+
+
+} // namespace CurveFitting
+} // namespace Mantid
+
+#endif  /* MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPCONVPV_H_ */