CLHEP/GenericFunctions/SymToArgAdaptor.hh

0001 // -*- C++ -*-
0002 // $Id:
0003 //-----------------------Class ParaToArgAdaptor-----------------------------//
0004 //                                                                          //
0005 //  Joe Boudreau                                                            //
0006 //  June 2004                                                               //
0007 //                                                                          //
0008 // The purpose of this adaptor is to be able to create, starting FROM       //
0009 // a function F of several variables and controlled by several parameters:  //
0010 //                                                                          //
0011 // F(alpha, beta, gamma....; x, y, z)                                       //
0012 //                                                                          //
0013 // a new function of several variables in which the parameter values are    //
0014 // set by some of the variables.  Application:  event-per-event errors.     //
0015 //                                                                          //
0016 // Arguments to the adaptor:                                                //
0017 // 1) The original generic function to adapt.                               //
0018 // 2) The symbolic expression to apply it to.                               //
0019 // 3) The name of a parameter to tweak.                                     //
0020 // 4) The symbolic expression to tweak it with                              //
0021 //                                                                          //
0022 //--------------------------------------------------------------------------//
0023 #ifndef _SYMTOARGADAPTOR_
0024 #define _SYMTOARGADAPTOR_
0025 #include <functional>
0026 #include <iostream>
0027 #include <string>
0028 #include "CLHEP/GenericFunctions/Parameter.hh"
0029 #include "CLHEP/GenericFunctions/AbsFunction.hh"
0030
0031 namespace Genfun {
0032
0033   template <class F>
0034   class SymToArgAdaptor : public AbsFunction  {
0035
0036     FUNCTION_OBJECT_DEF(SymToArgAdaptor)
0037
0038       public:
0039
0040     // ScopedMethodName
0041     typedef Parameter & (F::*ScopedMethodPtr) ();
0042
0043     // Constructor
0044     SymToArgAdaptor( F & function,                     // A function.
0045             const AbsFunction &  f_expression,                // An expression to apply it to
0046             ScopedMethodPtr      parameterFetchMethod,        // A parameter.
0047             const AbsFunction *  p_expression);               // An expression for the parameter
0048
0049     // Copy constructor
0050     SymToArgAdaptor(const SymToArgAdaptor &right);
0051
0052     // Destructor
0053     virtual ~SymToArgAdaptor();
0054
0055     // Retreive function value
0056     virtual double operator ()(double argument) const override;    // Gives an error.
0057     virtual double operator ()(const Argument & a) const override; // Must use this one
0058
0059     // Dimensionality
0060     virtual unsigned int dimensionality() const override;
0061
0062   private:
0063
0064     // It is illegal to assign an adjustable constant
0065     const SymToArgAdaptor & operator=(const SymToArgAdaptor &right);
0066
0067     // Here is the function being adapted;
0068     F *_function;
0069
0070     // A Variable (int an argument) to which the function is going to apply:
0071     const AbsFunction *_f_expression;
0072
0073     // Here is the recipe for fetching the parameter from the function:
0074     std::mem_fun_ref_t<Parameter &, F> _parameterFetchMethod;
0075
0076     // Here is the symbol to be connect to the parameter:
0077     const AbsFunction *_p_expression;
0078
0079   };
0080 } // namespace Genfun
0081   #include "CLHEP/GenericFunctions/SymToArgAdaptor.icc"
0082 #endif
0083