// @(#)root/hist:$Name:  $:$Id: TFormula.h,v 1.17 2002/10/31 07:27:36 brun Exp $
// Author: Nicolas Brun   19/08/95

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
// ---------------------------------- Formula.h

#ifndef ROOT_TFormula
#define ROOT_TFormula



//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TFormula                                                             //
//                                                                      //
// The formula base class  f(x,y,z,par)                                 //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#ifndef ROOT_TNamed
#include "TNamed.h"
#endif
#ifndef ROOT_TBits
#include "TBits.h"
#endif

const Int_t kMAXFOUND = 200;

class TFormula : public TNamed {

protected:

  Int_t     fNdim;            //Dimension of function (1=1-Dim, 2=2-Dim,etc)
  Int_t     fNpar;            //Number of parameters
  Int_t     fNoper;           //Number of operators
  Int_t     fNconst;          //Number of constants
  Int_t     fNumber;          //formula number identifier
  Int_t     fNval;            //Number of different variables in expression
  Int_t     fNstring;         //Number of different constants character strings
  TString   *fExpr;           //[fNoper] List of expressions
  Int_t     *fOper;           //[fNoper] List of operators
  Double_t  *fConst;          //[fNconst] Array of fNconst formula constants
  Double_t  *fParams;         //[fNpar] Array of fNpar parameters
  TString   *fNames;          //[fNpar] Array of parameter names
  TBits     fAlreadyFound;    //! cache for information

public:
    // TFormula status bits
    enum {
       kNotGlobal     = BIT(10)  // don't store in gROOT->GetListOfFunction
    };
           TFormula();
           TFormula(const char *name,const char *formula);
           TFormula(const TFormula &formula);
 virtual   ~TFormula();
 virtual void       Analyze(const char *schain, Int_t &err, Int_t offset=0);
 virtual Int_t      Compile(const char *expression="");
 virtual void       Copy(TObject &formula) const;
 virtual char       *DefinedString(Int_t code);
 virtual Double_t   DefinedValue(Int_t code);
 virtual Int_t      DefinedVariable(TString &variable);
 virtual Double_t   Eval(Double_t x, Double_t y=0, Double_t z=0, Double_t t=0);
 virtual Double_t   EvalPar(const Double_t *x, const Double_t *params=0);
 virtual Int_t      GetNdim() const {return fNdim;}
 virtual Int_t      GetNpar() const {return fNpar;}
 virtual Int_t      GetNumber() const {return fNumber;}
 Double_t           GetParameter(Int_t ipar) const;
 Double_t           GetParameter(const char *name) const;
 virtual Double_t  *GetParameters() const {return fParams;}
 virtual void       GetParameters(Double_t *params){for(Int_t i=0;i<fNpar;i++) params[i] = fParams[i];}
 virtual const char *GetParName(Int_t ipar) const;
 virtual Int_t      GetParNumber(const char *name) const;
 virtual void       Print(Option_t *option="") const; // *MENU*
 virtual void       SetNumber(Int_t number) {fNumber = number;}
 virtual void       SetParameter(const char *name, Double_t parvalue);
 virtual void       SetParameter(Int_t ipar, Double_t parvalue);
 virtual void       SetParameters(const Double_t *params);
 virtual void       SetParameters(Double_t p0,Double_t p1,Double_t p2=0,Double_t p3=0,Double_t p4=0
                       ,Double_t p5=0,Double_t p6=0,Double_t p7=0,Double_t p8=0,Double_t p9=0,Double_t p10=0); // *MENU*
 virtual void       SetParName(Int_t ipar, const char *name);
 virtual void       SetParNames(const char *name0="p0",const char *name1="p1",const char
                            *name2="p2",const char *name3="p3",const char
                            *name4="p4", const char *name5="p5",const char *name6="p6",const char *name7="p7",const char
                            *name8="p8",const char *name9="p9",const char *name10="p10"); // *MENU*
 virtual void       Update() {;}

 ClassDef(TFormula,4)  //The formula base class  f(x,y,z,par)
};

#endif