Re #5822. Added TabulatedFunction

Code/Mantid/Framework/API/src/IFunction.cpp

@@ -405,6 +405,7 @@ std::string IFunction::Attribute::asUnquotedString()const
       "as string");
   }
   std::string unquoted(attr);
+  if ( attr.empty() ) return "";
   if( *(attr.begin()) == '\"' ) unquoted = std::string(attr.begin() + 1, attr.end() - 1);
   if( *(unquoted.end() - 1) == '\"' ) unquoted = std::string(unquoted.begin(), unquoted.end() - 1);
 

Code/Mantid/Framework/CurveFitting/CMakeLists.txt

@@ -64,6 +64,7 @@ set ( SRC_FILES
 	src/SteepestDescentMinimizer.cpp
 	src/StretchExp.cpp
 	src/StretchExpMuon.cpp
+	src/TabulatedFunction.cpp
 	src/ThermalNeutronBk2BkExpConvPV.cpp
 	src/UserFunction.cpp
 	src/UserFunction1D.cpp
@@ -144,6 +145,7 @@ set ( INC_FILES
 	inc/MantidCurveFitting/SteepestDescentMinimizer.h
 	inc/MantidCurveFitting/StretchExp.h
 	inc/MantidCurveFitting/StretchExpMuon.h
+	inc/MantidCurveFitting/TabulatedFunction.h
 	inc/MantidCurveFitting/ThermalNeutronBk2BkExpConvPV.h
 	inc/MantidCurveFitting/UserFunction.h
 	inc/MantidCurveFitting/UserFunction1D.h
@@ -205,6 +207,7 @@ set ( TEST_FILES
 	StaticKuboToyabeTest.h
 	StretchExpMuonTest.h
 	StretchExpTest.h
+	TabulatedFunctionTest.h
 	ThermalNeutronBk2BkExpConvPVTest.h
 	UserFunction1DTest.h
 	UserFunctionTest.h

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

@@ -0,0 +1,138 @@
+#ifndef MANTID_CURVEFITTING_TABULATEDFUNCTION_H_
+#define MANTID_CURVEFITTING_TABULATEDFUNCTION_H_
+
+//----------------------------------------------------------------------
+// Includes
+//----------------------------------------------------------------------
+#include "MantidAPI/ParamFunction.h"
+#include "MantidAPI/IFunction1D.h"
+#include "MantidKernel/System.h"
+#include <cmath>
+
+namespace Mantid
+{
+
+//----------------------------------------------------------------------
+// Forward declaration
+//----------------------------------------------------------------------
+namespace API
+{
+  class MatrixWorkspace;
+}
+
+namespace CurveFitting
+{
+/**
+
+A function which takes its values from a file or a workspace. The values atr tabulated as
+x,y pairs. Liear interpolation is used for points between the tabulated values. The function
+returns zero for points outside the tabulated values.
+
+The function has two attributes: FileName and Workspace. They define a data set to take the values from.
+Setting one of the attributes clears the other. 
+
+The files can be either ascii text files or nexus files. The ascii files must contain two column
+of real numbers separated by spaces. The first column are the x-values and the second one is for y.
+
+If a nexus file is used its first spectrum provides the data for the function. The same is true for 
+a workspace which must be a MatrixWorkspace.
+
+The function has a signle parameter - a scaling factor "Scaling". 
+
+@author Roman Tolchenov, Tessella plc
+@date 4/09/2012
+
+Copyright &copy; 2007-8 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 TabulatedFunction : public API::ParamFunction, public API::IFunction1D
+{
+public:
+  /// Constructor
+  TabulatedFunction();
+
+  /// overwrite IFunction base class methods
+  std::string name()const{return "TabulatedFunction";}
+  virtual const std::string category() const { return "General";}
+  void function1D(double* out, const double* xValues, const size_t nData)const;
+  ///  function derivatives
+  void functionDeriv1D(API::Jacobian* out, const double* xValues, const size_t nData);
+
+  /// Returns the number of attributes associated with the function
+  size_t nAttributes()const{return 2;}
+  /// Returns a list of attribute names
+  std::vector<std::string> getAttributeNames()const;
+  /// Return a value of attribute attName
+  IFunction::Attribute getAttribute(const std::string& attName)const;
+  /// Set a value to attribute attName
+  void setAttribute(const std::string& attName,const IFunction::Attribute& value);
+  /// Check if attribute attName exists
+  bool hasAttribute(const std::string& attName)const{return attName == "FileName";}
+
+private:
+
+  /// Call the appropriate load function
+  void load(const std::string& fname);
+
+  /// Load the points from an ASCII file
+  void loadAscii(const std::string& fname);
+
+  /// Load the points from a NeXuS file
+  void loadNexus(const std::string& fname);
+
+  /// Load the points from a MatrixWorkspace
+  void loadWorkspace(const std::string& wsName);
+
+  /// Load the points from a MatrixWorkspace
+  void loadWorkspace(boost::shared_ptr<API::MatrixWorkspace> ws);
+
+  /// Size of the data
+  size_t size()const{return m_yData.size();}
+
+  /// Clear all data
+  void clear();
+
+  /// Evaluate the function for a list of arguments and given scaling factor
+  void eval(double scaling, double* out, const double* xValues, const size_t nData)const;
+
+  /// The file name
+  std::string m_fileName;
+
+  /// The workspace name
+  std::string m_wsName;
+
+  /// Stores x-values
+  std::vector<double> m_xData;
+
+  /// Stores y-values
+  std::vector<double> m_yData;
+
+  /// The first x
+  double m_xStart;
+
+  /// The lasst x
+  double m_xEnd;
+
+};
+
+} // namespace CurveFitting
+} // namespace Mantid
+
+#endif /*MANTID_CURVEFITTING_TABULATEDFUNCTION_H_*/