// @(#)root/mathmore:$Name:  $:$Id: GSLRootFinder.h,v 1.1 2005/09/18 17:33:47 brun Exp $
// Authors: L. Moneta, A. Zsenei   08/2005

 /**********************************************************************
  *                                                                    *
  * Copyright (c) 2004 ROOT Foundation,  CERN/PH-SFT                   *
  *                                                                    *
  * This library is free software; you can redistribute it and/or      *
  * modify it under the terms of the GNU General Public License        *
  * as published by the Free Software Foundation; either version 2     *
  * of the License, or (at your option) any later version.             *
  *                                                                    *
  * This library is distributed in the hope that it will be useful,    *
  * but WITHOUT ANY WARRANTY; without even the implied warranty of     *
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU   *
  * General Public License for more details.                           *
  *                                                                    *
  * You should have received a copy of the GNU General Public License  *
  * along with this library (see file COPYING); if not, write          *
  * to the Free Software Foundation, Inc., 59 Temple Place, Suite      *
  * 330, Boston, MA 02111-1307 USA, or contact the author.             *
  *                                                                    *
  **********************************************************************/

// Header file for class GSLRootFinder
//
// Created by: moneta  at Sun Nov 14 11:27:11 2004
//
// Last update: Sun Nov 14 11:27:11 2004
//
#ifndef ROOT_Math_GSLRootFinder
#define ROOT_Math_GSLRootFinder

#include "Math/IGenFunction.h"
#include "Math/GSLFunctionAdapter.h"

namespace ROOT {
namespace Math {


   class GSLRootFSolver;
   class GSLFunctionWrapper;


  /**
     Base class for GSL Root-Finding algorithms for one dimensional functions which do not use function derivatives.
     For finding the roots users should instantiate the RootFinder class with the corresponding algorithms
     See mathlib::RootFinder class for documentation.
     See the GSL <A HREF="http://www.gnu.org/software/gsl/manual/gsl-ref_32.html#SEC428"> online manual</A> for
     information on the GSL Root-Finding algorithms

     @ingroup RootFinders
  */


   class GSLRootFinder {

   public:
     GSLRootFinder();
     virtual ~GSLRootFinder();

   private:
     // usually copying is non trivial, so we make this unaccessible
     GSLRootFinder(const GSLRootFinder &);
     GSLRootFinder & operator = (const GSLRootFinder &);

   public:


     void SetFunction( const IGenFunction & f, double Root) {
       SetFunction( f, Root -1, Root + 1); // temporary
     }

     /**
     void SetFunction( const IGenFunction & f, double xlow, double xup) {
       const void * p = &f;
       SetFunction(  &GSLFunctionAdapter<IGenFunction>::F, const_cast<void *>(p), xlow, xup );
     }
     */
     void SetFunction( const IGenFunction & f, double xlow, double xup);

     typedef double ( * GSLFuncPointer ) ( double, void *);
     void SetFunction( GSLFuncPointer  f, void * params, double xlow, double xup);

     int Iterate();

     double Root() const;

     //double XLower() const;

     //double XUpper() const;

     // Solve for roots
     int Solve( int maxIter = 100, double absTol = 1E-3, double relTol = 1E-6);

     int Iterations() const {
       return fIter;
     }

     const char * Name() const;


   protected:


     void SetSolver (  GSLRootFSolver * s );

     void FreeSolver();

   private:

     GSLFunctionWrapper * fFunction;
     GSLRootFSolver * fS;

   protected:



   private:

     double fRoot;
     double fXlow;
     double fXup;
     int fIter;

   };

} // namespace Math
} // namespace ROOT


#endif /* ROOT_Math_GSLRootFinder */