Interface (abstract class) for one-dimensional functions providing a gradient calculation.
It implements both the ROOT::Math::IBaseFunctionOneDim and ROOT::Math::IGradientOneDim interfaces. The method ROOT::Math::IFunction::Derivative calculates the derivative and ROOT::Math::Fdf calculates the derivative and the function values at the same time. The pure private virtual method DoDerivative() must be implemented by the derived classes, while FdF is by default implemented using DoDerivative, but it can be overloaded by the derived classes to improve the efficiency in the derivative calculation.
Definition at line 381 of file IFunction.h.
Public Types | |
typedef IBaseFunctionOneDim | BaseFunc |
typedef IGradientOneDim | BaseGrad |
Public Types inherited from ROOT::Math::IBaseFunctionOneDim | |
typedef IBaseFunctionOneDim | BaseFunc |
Public Member Functions | |
virtual | ~IGradientFunctionOneDim () |
Virtual Destructor (no operations) More... | |
virtual void | FdF (double x, double &f, double &df) const |
Optimized method to evaluate at the same time the function value and derivative at a point x. More... | |
Public Member Functions inherited from ROOT::Math::IBaseFunctionOneDim | |
IBaseFunctionOneDim () | |
virtual | ~IBaseFunctionOneDim () |
virtual destructor More... | |
virtual IBaseFunctionOneDim * | Clone () const =0 |
Clone a function. More... | |
double | operator() (const double *x) const |
Evaluate the function at a point x[]. More... | |
double | operator() (double x) const |
Evaluate the function at a point x Use the a pure virtual private method DoEval which must be implemented by sub-classes. More... | |
Public Member Functions inherited from ROOT::Math::IGradientOneDim | |
virtual | ~IGradientOneDim () |
virtual destructor More... | |
double | Derivative (const double *x) const |
Compatibility method with multi-dimensional interface for partial derivative. More... | |
double | Derivative (double x) const |
Return the derivative of the function at a point x Use the private method DoDerivative. More... | |
void | FdF (const double *x, double &f, double *df) const |
Compatibility method with multi-dimensional interface for Gradient and function evaluation. More... | |
virtual void | FdF (double x, double &f, double &df) const =0 |
Optimized method to evaluate at the same time the function value and derivative at a point x. More... | |
void | Gradient (const double *x, double *g) const |
Compatibility method with multi-dimensional interface for Gradient. More... | |
#include <Math/IFunction.h>
Definition at line 388 of file IFunction.h.
Definition at line 389 of file IFunction.h.
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inlinevirtual |
Virtual Destructor (no operations)
Definition at line 395 of file IFunction.h.
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inlinevirtual |
Optimized method to evaluate at the same time the function value and derivative at a point x.
Often both value and derivatives are needed and it is often more efficient to compute them at the same time. Derived class should implement this method if performances play an important role and if it is faster to evaluate value and derivative at the same time
Implements ROOT::Math::IGradientOneDim.
Definition at line 405 of file IFunction.h.