TH1Merger.h

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// @(#)root/cont:$Id$
// Author:  Lorenzo Moneta 08/2016
 
/*************************************************************************
 * Copyright (C) 1995-2003, Rene Brun, Fons Rademakers and al.           *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
// Helper clas implementing some of the TH1 functionality
 
#include "TH1.h"
#include "TProfile.h"
#include "TProfile2D.h"
#include "TProfile3D.h"
#include "TList.h"
 
class TH1Merger {
 
public:
   enum EMergerType {
      kNotCompatible = -1,   // histogram arenot compatible and cannot be merged
      kAllSameAxes = 0,      // histogram have all some axes
      kAllNoLimits = 1,      // all histogram don't have limits (the buffer is used)
      kHasNewLimits = 2,     // some histogram have different limits but are compatibles
      kAllLabel = 3,         // histogram have labels all axis and same limits
      kLabelAndNewLimits = 4, // histogram have label but also some axes with different limits
      kAutoP2HaveLimits = 5, // P2 (power-of-2) algorithm: all histogram have limits
      kAutoP2NeedLimits = 6  // P2 algorithm: some histogram still need projections
   };
 
   static Bool_t AxesHaveLimits(const TH1 * h);
 
   static Int_t FindFixBinNumber(Int_t ibin, const TAxis & inAxis, const TAxis & outAxis) {
      // should I ceck in case of underflow/overflow if underflow/overflow values of input axis
      // outside  output axis ?
      if (ibin == 0 ) return 0;   // return underflow
      if (ibin == inAxis.GetNbins()+1 ) return outAxis.GetNbins()+1; // return overflow
      return outAxis.FindFixBin(inAxis.GetBinCenter(ibin));
   }
 
   // find bin number estending the axis
   static Int_t FindBinNumber(Int_t ibin, const TAxis & inAxis, TAxis & outAxis) {
      // should I ceck in case of underflow/overflow if underflow/overflow values of input axis
      // outside  output axis ?
      if (ibin == 0 ) return 0;   // return underflow
      if (ibin == inAxis.GetNbins()+1 ) return outAxis.GetNbins()+1; // return overflow
      return outAxis.FindBin(inAxis.GetBinCenter(ibin));
   }
 
   // Function to find if axis label list  has duplicates
   static Bool_t HasDuplicateLabels(const THashList * labels);
 
    // check if histogram has duplicate labels
   static Int_t CheckForDuplicateLabels(const TH1 * hist);
 
    // function to check if histogram bin is empty
   static Bool_t IsBinEmpty(const TH1 *hist, Int_t bin, Int_t profileDim = 0);
 
 
 
   TH1Merger(TH1 & h, TCollection & l, Option_t * opt = "") :
      fH0(&h),
      fHClone(nullptr),
      fNewAxisFlag(0)
   {
      fInputList.AddAll(&l);
      TString option(opt);
      if (!option.IsNull() ) {
         option.ToUpper();
         if (option.Contains("NOL") )
            fNoLabelMerge = true;
          if (option.Contains("NOCHECK") )
            fNoCheck = true;
      }
      TClass *classType = h.IsA();
      if (classType == TProfile::Class()) {
         fIsProfileMerge = kTRUE;
         fIsProfile1D = kTRUE;
      } else if (classType == TProfile2D::Class()) {
         fIsProfileMerge = kTRUE;
         fIsProfile2D = kTRUE;
      } else if (classType == TProfile3D::Class()) {
         fIsProfileMerge = kTRUE;
         fIsProfile3D = kTRUE;
      }
   }
 
   ~TH1Merger() {
      // The list contains fHClone, so let's clear it first to avoid
      // accessing deleted memory later [we 'could' have just removed
      // fHClone from the list]
      fInputList.Clear();
      if (fHClone) delete fHClone;
   }
 
   // function doing the actual merge
   Bool_t operator() ();
 
private:
   Bool_t AutoP2BuildAxes(TH1 *);
 
   EMergerType ExamineHistograms();
 
   void DefineNewAxes();
 
   void CopyBuffer(TH1 *hsrc, TH1 *hdes);
 
   Bool_t BufferMerge();
 
   Bool_t AutoP2BufferMerge();
 
   Bool_t AutoP2Merge();
 
   Bool_t SameAxesMerge();
 
   Bool_t DifferentAxesMerge();
 
   Bool_t LabelMerge(bool newLimits = false);
 
   template <class TProfileType>
   void MergeProfileBin(const TProfileType *p, Int_t ibin, Int_t outbin);
 
   // function doing the bin merge for histograms and profiles
   void MergeBin(const TH1 *hist, Int_t inbin, Int_t outbin);
 
   void MergeBin(const TProfile *hist, Int_t inbin, Int_t outbin) { MergeProfileBin<TProfile>(hist, inbin, outbin); }
   void MergeBin(const TProfile2D *hist, Int_t inbin, Int_t outbin) { MergeProfileBin<TProfile2D>(hist, inbin, outbin); }
   void MergeBin(const TProfile3D *hist, Int_t inbin, Int_t outbin) { MergeProfileBin<TProfile3D>(hist, inbin, outbin); }
 
   Bool_t fNoLabelMerge = kFALSE; // force merger to not use labels and do bin center by bin center
   Bool_t fNoCheck = kFALSE;      // skip check on duplicate labels
   Bool_t fIsProfileMerge = kFALSE; // flag to indicate if is a merge of TProfiles
   Bool_t fIsProfile1D = kFALSE;
   Bool_t fIsProfile2D = kFALSE;
   Bool_t fIsProfile3D = kFALSE;
   TH1 *fH0;                      ///<! histogram on which the list is merged
   TH1 *fHClone;                  ///<! copy of fH0 - managed by this class
   TList fInputList;              // input histogram List
   TAxis fNewXAxis;
   TAxis fNewYAxis;
   TAxis fNewZAxis;
   UInt_t fNewAxisFlag;
};