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FCNBase.h
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1// @(#)root/minuit2:$Id$
2// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei 2003-2005
3
4/**********************************************************************
5 * *
6 * Copyright (c) 2005 LCG ROOT Math team, CERN/PH-SFT *
7 * *
8 **********************************************************************/
9
10#ifndef ROOT_Minuit2_FCNBase
11#define ROOT_Minuit2_FCNBase
12
13#include "Minuit2/MnConfig.h"
14
15#include <vector>
16
18
19namespace ROOT {
20
21namespace Minuit2 {
22
23/**
24
25 \defgroup Minuit Minuit2 Minimization Library
26
27 New Object-oriented implementation of the MINUIT minimization package.
28 More information is available at the home page of the \ref Minuit2Page "Minuit2" minimization package".
29
30 \ingroup Math
31*/
32
33//______________________________________________________________________________
34/**
35
36
37Interface (abstract class) defining the function to be minimized, which has to be implemented by the user.
38
39@author Fred James and Matthias Winkler; modified by Andras Zsenei and Lorenzo Moneta
40
41\ingroup Minuit
42
43 */
44
45class FCNBase : public GenericFunction {
46
47public:
48 virtual ~FCNBase() {}
49
50 /**
51
52 The meaning of the vector of parameters is of course defined by the user,
53 who uses the values of those parameters to calculate their function Value.
54 The order and the position of these parameters is strictly the one specified
55 by the user when supplying the starting values for minimization. The starting
56 values must be specified by the user, either via an std::vector<double> or the
57 MnUserParameters supplied as input to the MINUIT minimizers such as
58 VariableMetricMinimizer or MnMigrad. Later values are determined by MINUIT
59 as it searches for the Minimum or performs whatever analysis is requested by
60 the user.
61
62 @param v function parameters as defined by the user.
63
64 @return the Value of the function.
65
66 @see MnUserParameters
67 @see VariableMetricMinimizer
68 @see MnMigrad
69
70 */
71
72 virtual double operator()(const std::vector<double> &v) const = 0;
73
74 /**
75
76 Error definition of the function. MINUIT defines Parameter errors as the
77 change in Parameter Value required to change the function Value by up. Normally,
78 for chisquared fits it is 1, and for negative log likelihood, its Value is 0.5.
79 If the user wants instead the 2-sigma errors for chisquared fits, it becomes 4,
80 as Chi2(x+n*sigma) = Chi2(x) + n*n.
81
82 Comment a little bit better with links!!!!!!!!!!!!!!!!!
83
84 */
85
86 virtual double ErrorDef() const { return Up(); }
87
88 /**
89
90 Error definition of the function. MINUIT defines Parameter errors as the
91 change in Parameter Value required to change the function Value by up. Normally,
92 for chisquared fits it is 1, and for negative log likelihood, its Value is 0.5.
93 If the user wants instead the 2-sigma errors for chisquared fits, it becomes 4,
94 as Chi2(x+n*sigma) = Chi2(x) + n*n.
95
96 \todo Comment a little bit better with links!!!!!!!!!!!!!!!!! Idem for ErrorDef()
97
98 */
99
100 virtual double Up() const = 0;
101
102 /**
103 add interface to set dynamically a new error definition
104 Re-implement this function if needed.
105 */
106 virtual void SetErrorDef(double){};
107};
108
109} // namespace Minuit2
110
111} // namespace ROOT
112
113#endif // ROOT_Minuit2_FCNBase
Interface (abstract class) defining the function to be minimized, which has to be implemented by the ...
Definition: FCNBase.h:45
virtual double Up() const =0
Error definition of the function.
virtual ~FCNBase()
Definition: FCNBase.h:48
virtual void SetErrorDef(double)
add interface to set dynamically a new error definition Re-implement this function if needed.
Definition: FCNBase.h:106
virtual double ErrorDef() const
Error definition of the function.
Definition: FCNBase.h:86
virtual double operator()(const std::vector< double > &v) const =0
The meaning of the vector of parameters is of course defined by the user, who uses the values of thos...
Class from which all the other classes, representing functions, inherit.
tbb::task_arena is an alias of tbb::interface7::task_arena, which doesn't allow to forward declare tb...
Definition: RNumpyDS.hxx:30