Logo ROOT   6.30.04
Reference Guide
 All Namespaces Files Pages
FCNGradientBase.h
Go to the documentation of this file.
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_FCNGradientBase
11 #define ROOT_Minuit2_FCNGradientBase
12 
13 #include "Minuit2/FCNBase.h"
14 
15 namespace ROOT {
16 
17  namespace Minuit2 {
18 
19 //________________________________________________________________________
20 /** Extension of the FCNBase for providing the analytical Gradient of the
21  function. The user-Gradient is checked at the beginning of the
22  minimization against the Minuit internal numerical Gradient in order to
23  spot problems in the analytical Gradient calculation. This can be turned
24  off by overriding CheckGradient() to make it return "false".
25  The size of the output Gradient vector must be equal to the size of the
26  input Parameter vector.
27  Minuit does a check of the user Gradient at the beginning, if this is not
28  wanted the method "CheckGradient()" has to be overridden to return
29  "false".
30  */
31 
32 class FCNGradientBase : public FCNBase {
33 
34 public:
35 
36  virtual ~FCNGradientBase() {}
37 
38  virtual std::vector<double> Gradient(const std::vector<double>&) const = 0;
39 
40  virtual bool CheckGradient() const {return true;}
41 
42 };
43 
44  } // namespace Minuit2
45 
46 } // namespace ROOT
47 
48 #endif // ROOT_Minuit2_FCNGradientBase