    // @(#)root/tree:$Name:  $:$Id: TNtuple.cxx,v 1.10 2005/04/07 10:57:32 brun Exp $
    // Author: Rene Brun   06/04/96

    /*************************************************************************
     * 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.             *
     *************************************************************************/

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TNtuple                                                              //
    //                                                                      //
    // A simple tree restricted to a list of float variables only.          //
    //                                                                      //
    // Each variable goes to a separate branch.                             //
    //                                                                      //
    //  A Ntuple is created via                                             //
    //     TNtuple(name,title,varlist,bufsize)                              //
    //  It is filled via:                                                   //
    //     TNtuple::Fill(*x)  or                                            //
    //     TNtuple::Fill(v1,v2,v3.....)                                     //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "TNtuple.h"
    #include "TTree.h"
    #include "TBranch.h"
    #include "TLeaf.h"
    #include "TBrowser.h"
    #include "Riostream.h"

    #include <string>

    ClassImp(TNtuple)

    //______________________________________________________________________________
     TNtuple::TNtuple(): TTree()
    {
    //*-*-*-*-*-*Default constructor for Ntuple*-*-*-*-*-*-*-*-*-*-*-*-*-*
    //*-*        ==============================

       fNvar = 0;
       fArgs = 0;
    }

    //______________________________________________________________________________
     TNtuple::TNtuple(const char *name, const char *title, const char *varlist, Int_t bufsize)
           :TTree(name,title)
    {
    //*-*-*-*-*-*-*-*-*-*-*-*-*Create an Ntuple*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
    //*-*                      ================
    //       The parameter varlist describes the list of the ntuple variables
    //       separated by a colon:
    //         example:  "x:y:z:energy"
    //       For each variable in the list a separate branch is created.
    //
    //       Use TTree to create branches with variables of different data types.
    //*-*

       Int_t i;
       fNvar = 0;
       fArgs = 0;

    //   Count number of variables (separated by :)
       Int_t nch = strlen(varlist);
       if (nch == 0) return;
       char *vars = new char[nch+1];
       strcpy(vars,varlist);
       Int_t *pvars = new Int_t[1000];
       fNvar = 1;
       pvars[0] = 0;
       for (i=1;i<nch;i++) {
          if (vars[i] == ':') {
             pvars[fNvar] = i+1;
             vars[i] = 0;
             fNvar++;
          }
       }
       fArgs = new Float_t[fNvar];

    //  Create one branch for each variable
       for (i=0;i<fNvar;i++) {
          Int_t pv = pvars[i];
          TTree::Branch(&vars[pv],&fArgs[i],&vars[pv],bufsize);
       }

       delete [] vars;
       delete [] pvars;
    }

    //______________________________________________________________________________
     TNtuple::~TNtuple()
    {
    //*-*-*-*-*-*Default destructor for an Ntuple*-*-*-*-*-*-*-*-*-*-*-*
    //*-*        ================================

       delete [] fArgs;
       fArgs = 0;
    }

    //______________________________________________________________________________
     void TNtuple::ResetBranchAddresses()
    {
       // Reset the branch addresses to the internal fArgs array. Use this
       // method when the addresses were changed via calls to SetBranchAddress().

       for (Int_t i = 0; i < fNvar; i++) {
          TBranch *branch = (TBranch*)fBranches.UncheckedAt(i);
          if (branch) branch->SetAddress(&fArgs[i]);
       }
    }

    //______________________________________________________________________________
     void TNtuple::Browse(TBrowser *b)
    {
        fLeaves.Browse( b );
    }

    //______________________________________________________________________________
     Int_t TNtuple::Fill()
    {
    //*-*-*-*-*-*-*-*-*Fill a Ntuple with current values in fArgs*-*-*-*-*-*-*
    //*-*              ==========================================
    // Note that this function is protected.
    // Currently called only by TChain::Merge

      return TTree::Fill();
    }

    //______________________________________________________________________________
     Int_t TNtuple::Fill(const Float_t *x)
    {
       // Fill a Ntuple with an array of floats

       // Store array x into buffer
       for (Int_t i=0;i<fNvar;i++)  {
          fArgs[i] = x[i];
       }

       return TTree::Fill();
    }

    //______________________________________________________________________________
     Int_t TNtuple::Fill(Float_t x0,Float_t x1,Float_t x2,Float_t x3,Float_t x4
                  ,Float_t x5,Float_t x6,Float_t x7,Float_t x8,Float_t x9
                  ,Float_t x10,Float_t x11,Float_t x12,Float_t x13,Float_t x14)
    {
       // Fill a Ntuple: Each Ntuple item is an argument

       if (fNvar >  0) fArgs[0]  = x0;
       if (fNvar >  1) fArgs[1]  = x1;
       if (fNvar >  2) fArgs[2]  = x2;
       if (fNvar >  3) fArgs[3]  = x3;
       if (fNvar >  4) fArgs[4]  = x4;
       if (fNvar >  5) fArgs[5]  = x5;
       if (fNvar >  6) fArgs[6]  = x6;
       if (fNvar >  7) fArgs[7]  = x7;
       if (fNvar >  8) fArgs[8]  = x8;
       if (fNvar >  9) fArgs[9]  = x9;
       if (fNvar > 10) fArgs[10] = x10;
       if (fNvar > 11) fArgs[11] = x11;
       if (fNvar > 12) fArgs[12] = x12;
       if (fNvar > 13) fArgs[13] = x13;
       if (fNvar > 14) fArgs[14] = x14;

       return TTree::Fill();
    }

    //_______________________________________________________________________
     Long64_t TNtuple::ReadFile(const char *filename, const char * /*branchDescriptor*/)
    {
       // Read from filename as many columns as variables in the ntuple
       // the function returns the number of rows found in the file
       // The second argument "branchDescriptor" is currently not used.
       // Lines in the input file starting with "#" are ignored.

       Long64_t nlines = 0;
       ifstream in;
       in.open(filename);
       while (1) {
         if ( in.peek() != '#' ) {
           for (Int_t i=0;i<fNvar;i++) in >> fArgs[i];
           if (!in.good()) break;
           TTree::Fill();
           nlines++;
         }
         in.ignore(8192,'\n');
       }
       in.close();
       return nlines;
    }

    //_______________________________________________________________________
     void TNtuple::Streamer(TBuffer &b)
    {
    //*-*-*-*-*-*-*-*-*Stream a class object*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
    //*-*              =========================================
       if (b.IsReading()) {
          UInt_t R__s, R__c;
          Version_t R__v = b.ReadVersion(&R__s, &R__c);
          if (R__v > 1) {
             TNtuple::Class()->ReadBuffer(b, this, R__v, R__s, R__c);
          } else {
             //====process old versions before automatic schema evolution
             TTree::Streamer(b);
             b >> fNvar;
             b.CheckByteCount(R__s, R__c, TNtuple::IsA());
             //====end of old versions
          }
          if (fNvar <= 0) return;
          fArgs = new Float_t[fNvar];
          for (Int_t i=0;i<fNvar;i++) {
             TBranch *branch = (TBranch*)fBranches.UncheckedAt(i);
             if (branch) branch->SetAddress(&fArgs[i]);
          }
       } else {
          TNtuple::Class()->WriteBuffer(b,this);
       }
    }