class ROOT::Minuit2::FumiliFCNBase: public ROOT::Minuit2::FCNBase
Extension of the FCNBase for the Fumili method. Fumili applies only to minimization problems used for fitting. The method is based on a linearization of the model function negleting second derivatives. User needs to provide the model function. The figure-of-merit describing the difference between the model function and the actual measurements has to be implemented by the user in a subclass of FumiliFCNBase. For an example see the FumiliChi2FCN and FumiliStandardChi2FCN classes. @author Andras Zsenei and Lorenzo Moneta, Creation date: 23 Aug 2004 @see <A HREF="http://www.cern.ch/winkler/minuit/tutorial/mntutorial.pdf">MINUIT Tutorial</A> on function minimization, section 5 @see FumiliChi2FCN @see FumiliStandardChi2FCN @ingroup Minuit
Function Members (Methods)
This is an abstract class, constructors will not be documented.
Look at the header to check for available constructors.
public:
protected:
| vector<double>& | Gradient() |
| vector<double>& | Hessian() |
| virtual void | InitAndReset(unsigned int npar) |
| void | SetFCNValue(double value) |
Class Charts
Function documentation
FumiliFCNBase()
Default Constructor. Need in this case to create when implementing EvaluateAll the Gradient and Hessian vectors with the right size
{} FumiliFCNBase(unsigned int npar)
Constructor which initializes the class with the function provided by the
user for modeling the data.
@param npar the number of parameters
{}virtual ~FumiliFCNBase()
FumiliFCNBase(const ParametricFunction& modelFCN) { fModelFunction = &modelFCN; }
{}void EvaluateAll(const vector<double>& par)
Evaluate function Value, Gradient and Hessian using Fumili approximation, for values of parameters p
The resul is cached inside and is return from the FumiliFCNBase::Value , FumiliFCNBase::Gradient and
FumiliFCNBase::Hessian methods
@param par vector of parameters
double Value() const
Return cached Value of objective function estimated previously using the FumiliFCNBase::EvaluateAll method
{ return fValue; }const std::vector<double> & Gradient() const
Return cached Value of function Gradient estimated previously using the FumiliFCNBase::EvaluateAll method
{ return fGradient; }double Hessian(unsigned int row, unsigned int col) const
Return Value of the i-th j-th element of the Hessian matrix estimated previously using the FumiliFCNBase::EvaluateAll method
@param row row Index of the matrix
@param col col Index of the matrix
unsigned int Dimension()
return number of function variable (parameters) , i.e. function dimension
{ return fNumberOfParameters; }void SetFCNValue(double value)
methods to be used by the derived classes to set the values
{ fValue = value; }