 |
ROOT
Reference Guide |
|
| |
ROOT
Reference Guide |
|
Interface (abstract class) for multi-dimensional functions providing a gradient calculation.
It implements both the ROOT::Math::IBaseFunctionMultiDimTempl and ROOT::Math::IGradientMultiDimTempl interfaces. The method ROOT::Math::IFunction::Gradient calculates the full gradient vector, ROOT::Math::IFunction::Derivative calculates the partial derivative for each coordinate and ROOT::Math::Fdf calculates the gradient and the function value at the same time. The pure private virtual method DoDerivative() must be implemented by the derived classes, while Gradient and FdF are by default implemented using DoDerivative, butthey can be overloaded by the derived classes to improve the efficiency in the derivative calculation.
Definition at line 326 of file IFunction.h.
Public Types | |
| typedef IBaseFunctionMultiDimTempl< T > | BaseFunc |
| typedef IGradientMultiDimTempl< T > | BaseGrad |
 Public Types inherited from ROOT::Math::IBaseFunctionMultiDimTempl< T > | |
| typedef T | BackendType |
| typedef IBaseFunctionMultiDimTempl< T > | BaseFunc |
Public Member Functions | |
| virtual | ~IGradientFunctionMultiDimTempl () |
| Virtual Destructor (no operations) More... | |
| virtual void | FdF (const T *x, T &f, T *df) const |
| Optimized method to evaluate at the same time the function value and derivative at a point x. More... | |
| virtual void | Gradient (const T *x, T *grad) const |
| Evaluate all the vector of function derivatives (gradient) at a point x. More... | |
| virtual unsigned int | NDim () const=0 |
| Retrieve the dimension of the function. More... | |
| Public Member Functions inherited from ROOT::Math::IBaseFunctionMultiDimTempl< T > | |
| IBaseFunctionMultiDimTempl () | |
| virtual | ~IBaseFunctionMultiDimTempl () |
| virtual destructor More... | |
| virtual IBaseFunctionMultiDimTempl< T > * | Clone () const =0 |
| Clone a function. More... | |
| virtual unsigned int | NDim () const =0 |
| Retrieve the dimension of the function. More... | |
| T | operator() (const T *x) const |
| Evaluate the function at a point x[]. More... | |
| Public Member Functions inherited from ROOT::Math::IGradientMultiDimTempl< T > | |
| virtual | ~IGradientMultiDimTempl () |
| virual destructor More... | |
| T | Derivative (const T *x, unsigned int icoord=0) const |
| Return the partial derivative with respect to the passed coordinate. More... | |
| virtual void | FdF (const T *x, T &f, T *df) const =0 |
| Optimized method to evaluate at the same time the function value and derivative at a point x. More... | |
| virtual void | Gradient (const T *x, T *grad) const =0 |
| Evaluate all the vector of function derivatives (gradient) at a point x. More... | |
#include <Math/IFunction.h>
| typedef IBaseFunctionMultiDimTempl<T> ROOT::Math::IGradientFunctionMultiDimTempl< T >::BaseFunc |
Definition at line 330 of file IFunction.h.
| typedef IGradientMultiDimTempl<T> ROOT::Math::IGradientFunctionMultiDimTempl< T >::BaseGrad |
Definition at line 331 of file IFunction.h.
|
inlinevirtual |
Virtual Destructor (no operations)
Definition at line 336 of file IFunction.h.
|
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::IGradientMultiDimTempl< T >.
Definition at line 357 of file IFunction.h.
|
inlinevirtual |
Evaluate all the vector of function derivatives (gradient) at a point x.
Derived classes must re-implement it if more efficient than evaluting one at a time
Implements ROOT::Math::IGradientMultiDimTempl< T >.
Definition at line 342 of file IFunction.h.
|
virtual |
Retrieve the dimension of the function.
Implements ROOT::Math::IBaseFunctionMultiDimTempl< T >.
