class ROOT::Math::RootFinder


         User Class to find the Root of one dimensional functions.
         The GSL Methods are implemented in MathMore and they are loaded automatically
         via the plug-in manager

         The possible types of Root-finding algorithms are:
         <ul>
         <li>Root Bracketing Algorithms which do not require function derivatives
         <ol>
         <li>RootFinder::kBRENT  (default method implemented in MathCore)
         <li>RootFinder::kGSL_BISECTION
         <li>RootFinder::kGSL_FALSE_POS
         <li>RootFinder::kGSL_BRENT
         </ol>
         <li>Root Finding Algorithms using Derivatives
         <ol>
         <li>RootFinder::kGSL_NEWTON
         <li>RootFinder::kGSL_SECANT
         <li>RootFinder::kGSL_STEFFENSON
         </ol>
         </ul>

         This class does not cupport copying

         @ingroup RootFinders

Function Members (Methods)

public:

virtual	~RootFinder()
int	Iterate()
int	Iterations() const
const char*	Name() const
double	Root() const
ROOT::Math::RootFinder	RootFinder(ROOT::Math::RootFinder::EType type = RootFinder::kBRENT)
bool	SetFunction(const ROOT::Math::IGradFunction& f, double xstart)
bool	SetFunction(const ROOT::Math::IGenFunction& f, double xlow, double xup)
bool	SetMethod(ROOT::Math::RootFinder::EType type = RootFinder::kBRENT)
bool	Solve(int maxIter = 100, double absTol = 1E-8, double relTol = 1E-10)
int	Status() const

private:

ROOT::Math::RootFinder&	operator=(const ROOT::Math::RootFinder& rhs)
ROOT::Math::RootFinder	RootFinder(const ROOT::Math::RootFinder&)

Data Members

public:

enum EType {	kBRENT
	kGSL_BISECTION
	kGSL_FALSE_POS
	kGSL_BRENT
	kGSL_NEWTON
	kGSL_SECANT
	kGSL_STEFFENSON
};

private:

ROOT::Math::IRootFinderMethod*	fSolver	type of algorithm to be used

Class Charts

Inheritance Inherited Members Includes Libraries

Function documentation

bool Solve(Function &f, Derivative &d, double start, int maxIter, double absTol, double relTol)

RootFinder(RootFinder::EType type = RootFinder::kBRENT)

            Construct a Root-Finder algorithm

virtual ~RootFinder()

RootFinder(const RootFinder & )

 usually copying is non trivial, so we make this unaccessible

{}

bool SetMethod(ROOT::Math::RootFinder::EType type = RootFinder::kBRENT)

bool SetFunction(const ROOT::Math::IGenFunction& f, double xlow, double xup)

            Provide to the solver the function and the initial search interval [xlow, xup]
            for algorithms not using derivatives (bracketing algorithms)
            The templated function f must be of a type implementing the \a operator() method,
            <em>  double  operator() (  double  x ) </em>
            Returns non zero if interval is not valid (i.e. does not contains a root)

return fSolver-> SetFunction(const ROOT::Math::IGenFunction& f, double xlow, double xup)

int Iterations() const

             Return the number of iteration performed to find the Root.

int Iterate()

            Perform a single iteration and return the Status

double Root() const

            Return the current and latest estimate of the Root

int Status() const

            Return the status of the last estimate of the Root
            = 0 OK, not zero failure

const char * Name() const

            Return the current and latest estimate of the lower value of the Root-finding interval (for bracketing algorithms)

double XLower() const {
return fSolver->XLower();
}

            Return the current and latest estimate of the upper value of the Root-finding interval (for bracketing algorithms)

double XUpper() const {
return  fSolver->XUpper();
}

            Get Name of the Root-finding solver algorithm