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GSLMultiMinFunctionAdapter.h
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1// @(#)root/mathmore:$Id$
2// Authors: L. Moneta, 12/2006
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 * *
18 * You should have received a copy of the GNU General Public License *
19 * along with this library (see file COPYING); if not, write *
20 * to the Free Software Foundation, Inc., 59 Temple Place, Suite *
21 * 330, Boston, MA 02111-1307 USA, or contact the author. *
22 * *
23 **********************************************************************/
24
25// Header file for class GSLMultiMinFunctionAdapter
26//
27// Generic adapter for gsl_multimin_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_GSLMultiMinFunctionAdapter
35#define ROOT_Math_GSLMultiMinFunctionAdapter
36
37#include "gsl/gsl_vector.h"
38
39namespace ROOT {
40namespace Math {
41
42
43
44
45 /**
46 Class for adapting any multi-dimension C++ functor class to C function pointers used by
47 GSL MultiMin algorithms.
48 The templated C++ function class must implement:
49
50 <em> double operator( const double * x)</em>
51 and if the derivatives are required:
52 <em> void Gradient( const double * x, double * g)</em>
53
54 This class defines static methods with will be used to fill the
55 \a gsl_multimin_function and
56 \a gsl_multimin_function_fdf structs used by GSL.
57 See for examples the
58 <A HREF="http://www.gnu.org/software/gsl/manual/html_node/Providing-a-function-to-minimize.html#Providing-a-function-to-minimize">GSL online manual</A>
59
60 @ingroup MultiMin
61
62 */
63
64
65 template<class UserFunc>
67
68 static double F( const gsl_vector * x, void * p) {
69
70 UserFunc * function = reinterpret_cast< UserFunc *> (p);
71 // get pointer to data from gsl_vector
72 return (*function)( x->data );
73 }
74
75
76 static void Df( const gsl_vector * x, void * p, gsl_vector * g) {
77
78 UserFunc * function = reinterpret_cast< UserFunc *> (p);
79 (*function).Gradient( x->data, g->data );
80
81 }
82
83 static void Fdf( const gsl_vector * x, void * p, double *f, gsl_vector * g ) {
84
85 UserFunc * function = reinterpret_cast< UserFunc *> (p);
86// *f = (*function) ( x );
87// *df = (*function).Gradient( x );
88
89 (*function).FdF( x->data, *f, g->data);
90 }
91
92 };
93
94
95} // namespace Math
96} // namespace ROOT
97
98
99#endif /* ROOT_Math_GSLMultiMinFunctionAdapter */
#define f(i)
Definition: RSha256.hxx:104
#define g(i)
Definition: RSha256.hxx:105
Double_t x[n]
Definition: legend1.C:17
Namespace for new Math classes and functions.
void function(const Char_t *name_, T fun, const Char_t *docstring=0)
Definition: RExports.h:151
Namespace for new ROOT classes and functions.
Definition: StringConv.hxx:21
Class for adapting any multi-dimension C++ functor class to C function pointers used by GSL MultiMin ...
static double F(const gsl_vector *x, void *p)
static void Df(const gsl_vector *x, void *p, gsl_vector *g)
static void Fdf(const gsl_vector *x, void *p, double *f, gsl_vector *g)