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Reference Guide
GSLFunctionAdapter.h
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1 // @(#)root/mathmore:$Id$
2 // Authors: L. Moneta, A. Zsenei 08/2005
3 
4  /**********************************************************************
5  * *
6  * Copyright (c) 2004 ROOT Foundation, CERN/PH-SFT *
7  * *
8  * This library is free software; you can redistribute it and/or *
9  * modify it under the terms of the GNU General Public License *
10  * as published by the Free Software Foundation; either version 2 *
11  * of the License, or (at your option) any later version. *
12  * *
13  * This library is distributed in the hope that it will be useful, *
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
16  * General Public License for more details. *
17  * *
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20  * to the Free Software Foundation, Inc., 59 Temple Place, Suite *
21  * 330, Boston, MA 02111-1307 USA, or contact the author. *
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23  **********************************************************************/
24 
25 // Header file for class GSLFunctionAdapter
26 //
27 // Generic adapter for gsl_function signature
28 // usable for any c++ class which defines operator( )
29 //
30 // Created by: Lorenzo Moneta at Fri Nov 12 16:58:51 2004
31 //
32 // Last update: Fri Nov 12 16:58:51 2004
33 //
34 #ifndef ROOT_Math_GSLFunctionAdapter
35 #define ROOT_Math_GSLFunctionAdapter
36 
37 
38 namespace ROOT {
39 namespace Math {
40 
41  /**
42  Function pointer corresponding to gsl_function signature
43  */
44 
45  typedef double ( * GSLFuncPointer ) ( double, void *);
46 
47 
48  /**
49  Class for adapting any C++ functor class to C function pointers used by GSL.
50  The templated C++ function class must implement:
51 
52  <em> double operator( double x)</em>
53  and if the derivatives are required:
54  <em> double Gradient( double x)</em>
55 
56  This class defines static methods with will be used to fill the
57  \a gsl_function and \a gsl_function_fdf structs used by GSL.
58  See for examples the <A HREF="http://www.gnu.org/software/gsl/manual/gsl-ref_32.html#SEC432">GSL online manual</A>
59  */
60 
61 
62  template<class UserFunc>
64 
65  public:
66 
68  virtual ~GSLFunctionAdapter() {}
69 
70  static double F( double x, void * p) {
71 
72  UserFunc * function = reinterpret_cast< UserFunc *> (p);
73  return (*function)( x );
74  }
75 
76 
77  static double Df( double x, void * p) {
78 
79  UserFunc * function = reinterpret_cast< UserFunc *> (p);
80  return (*function).Derivative( x );
81  }
82 
83  static void Fdf( double x, void * p, double *f, double *df ) {
84 
85  UserFunc * function = reinterpret_cast< UserFunc *> (p);
86  *f = (*function) ( x );
87  *df = (*function).Derivative( x );
88  }
89 
90  };
91 
92 
93 } // namespace Math
94 } // namespace ROOT
95 
96 
97 #endif /* ROOT_Math_GSLFunctionAdapter */
static void Fdf(double x, void *p, double *f, double *df)
Namespace for new ROOT classes and functions.
Definition: StringConv.hxx:21
#define f(i)
Definition: RSha256.hxx:104
Double_t x[n]
Definition: legend1.C:17
static double Df(double x, void *p)
double(* GSLFuncPointer)(double, void *)
Function pointer corresponding to gsl_function signature.
Class for adapting any C++ functor class to C function pointers used by GSL.
Namespace for new Math classes and functions.
static double F(double x, void *p)