// @(#)root/minuit2:$Id$
// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei   2003-2005  

/**********************************************************************
 *                                                                    *
 * Copyright (c) 2005 LCG ROOT Math team,  CERN/PH-SFT                *
 *                                                                    *
 **********************************************************************/

#ifndef ROOT_Minuit2_FumiliBuilder
#define ROOT_Minuit2_FumiliBuilder

#include "Minuit2/MinimumBuilder.h"
#include "Minuit2/VariableMetricEDMEstimator.h"
#include "Minuit2/FumiliErrorUpdator.h"
#include "Minuit2/MnFcn.h"
#include "Minuit2/FunctionMinimum.h"

namespace ROOT {

   namespace Minuit2 {


/**

Builds the FunctionMinimum using the Fumili method.

@author Andras Zsenei, Creation date: 29 Sep 2004

@see <A HREF="http://www.cern.ch/winkler/minuit/tutorial/mntutorial.pdf">MINUIT Tutorial</A> on function minimization, section 5

@ingroup Minuit

\todo the role of the strategy in Fumili

*/



class FumiliBuilder : public MinimumBuilder {

public:

  FumiliBuilder() : fEstimator(VariableMetricEDMEstimator()), 
   fErrorUpdator(FumiliErrorUpdator()) {}

  ~FumiliBuilder() {}


  /**

  Class the member function calculating the Minimum and verifies the result
  depending on the strategy.

  @param fMnFcn the function to be minimized.

  @param fGradienCalculator not used in Fumili.

  @param fMinimumSeed the seed generator.

  @param fMnStrategy the strategy describing the number of function calls 
  allowed for Gradient calculations.

  @param maxfcn maximum number of function calls after which the calculation 
  will be stopped even if it has not yet converged.

  @param edmval expected vertical distance to the Minimum.

  @return Returns the function Minimum found.


  \todo Complete the documentation by understanding what is the reason to 
  have two Minimum methods.

  */

  virtual FunctionMinimum Minimum(const MnFcn& fMnFcn, const GradientCalculator& fGradienCalculator, const MinimumSeed& fMinimumSeed, const MnStrategy& fMnStrategy, unsigned int maxfcn, double edmval) const;


  /**

  Calculates the Minimum based on the Fumili method

  @param fMnFcn the function to be minimized.

  @param fGradienCalculator not used in Fumili

  @param fMinimumSeed the seed generator.

  @param states vector containing the state result of each iteration  

  @param maxfcn maximum number of function calls after which the calculation 
  will be stopped even if it has not yet converged.

  @param edmval expected vertical distance to the Minimum

  @return Returns the function Minimum found.

  @see <A HREF="http://www.cern.ch/winkler/minuit/tutorial/mntutorial.pdf">MINUIT Tutorial</A> on function minimization, section 5


  \todo some nice Latex based formula here...

  */

  FunctionMinimum Minimum(const MnFcn& fMnFcn, const GradientCalculator& fGradienCalculator, const MinimumSeed& fMinimumSeed, std::vector<MinimumState> & states, unsigned int maxfcn, double edmval) const;
 

  /**

  Accessor to the EDM (expected vertical distance to the Minimum) estimator.

  @return The EDM estimator used in the builder.

  \todo Maybe a little explanation concerning EDM in all relevant classes.

  */
 
  const VariableMetricEDMEstimator& Estimator() const {return fEstimator;}


  /**

  Accessor to the Error updator of the builder.

  @return The FumiliErrorUpdator used by the FumiliBuilder.

  */

  const FumiliErrorUpdator& ErrorUpdator() const {return fErrorUpdator;}


private:

  VariableMetricEDMEstimator fEstimator;
  FumiliErrorUpdator fErrorUpdator;
};

  }  // namespace Minuit2

}  // namespace ROOT

#endif  // ROOT_Minuit2_FumiliBuilder