diff --git a/include/Rivet/Tools/RivetYODA.hh b/include/Rivet/Tools/RivetYODA.hh
--- a/include/Rivet/Tools/RivetYODA.hh
+++ b/include/Rivet/Tools/RivetYODA.hh
@@ -1,716 +1,716 @@
 #ifndef RIVET_RIVETYODA_HH
 #define RIVET_RIVETYODA_HH
 
 #include "Rivet/Config/RivetCommon.hh"
 #include "YODA/AnalysisObject.h"
 #include "YODA/Counter.h"
 #include "YODA/Histo1D.h"
 #include "YODA/Histo2D.h"
 #include "YODA/Profile1D.h"
 #include "YODA/Profile2D.h"
 #include "YODA/Scatter1D.h"
 #include "YODA/Scatter2D.h"
 #include "YODA/Scatter3D.h"
 
 #include <map>
 #include <valarray>
 
 namespace YODA {
 
   typedef std::shared_ptr<YODA::AnalysisObject> AnalysisObjectPtr;
 
   typedef std::shared_ptr<YODA::Counter> CounterPtr;
   typedef std::shared_ptr<YODA::Histo1D> Histo1DPtr;
   typedef std::shared_ptr<YODA::Histo2D> Histo2DPtr;
   typedef std::shared_ptr<YODA::Profile1D> Profile1DPtr;
   typedef std::shared_ptr<YODA::Profile2D> Profile2DPtr;
   typedef std::shared_ptr<YODA::Scatter1D> Scatter1DPtr;
   typedef std::shared_ptr<YODA::Scatter2D> Scatter2DPtr;
   typedef std::shared_ptr<YODA::Scatter3D> Scatter3DPtr;
 
 }
 
 
 namespace Rivet {
 
 
   class AnalysisObjectWrapper {
   public:
     virtual ~AnalysisObjectWrapper() {}
 
     virtual YODA::AnalysisObject* operator->() = 0;
     virtual YODA::AnalysisObject* operator->() const = 0;
     virtual const YODA::AnalysisObject & operator*() const = 0;
 
     /// @todo Rename to setActive(idx)
     virtual void setActiveWeightIdx(unsigned int iWeight) = 0;
 
     /// @todo Set active object for finalize
     virtual void setActiveFinalWeightIdx(unsigned int iWeight) = 0;
 
     virtual void unsetActiveWeight() = 0;
 
     bool operator ==(const AnalysisObjectWrapper& p) { return (this == &p); }
     bool operator !=(const AnalysisObjectWrapper& p) { return (this != &p); }
 
   protected:
     /// @todo do we need this?
     // virtual void reset() = 0;
   };
 
   /// @todo
   /// implement scatter1dptr and scatter2dptr here
   /// these need to be multi-weighted eventually.
   /*
     class Scatter1DPtr : public AnalysisObjectPtr {
     public:
     Scatter1DPtr() : _persistent() { }
 
     Scatter1DPtr(size_t len_of_weightvec, const YODA::Scatter1D& p) {
     for (size_t m = 0; m < len_of_weightvec; ++m)
     _persistent.push_back(make_shared<YODA::Scatter1D>(p));
     }
 
     bool operator!() const { return !_persistent; }
     explicit operator bool() const { return bool(_persistent); }
 
     YODA::Scatter1D* operator->() { return _persistent.get(); }
 
     YODA::Scatter1D* operator->() const { return _persistent.get(); }
 
     YODA::Scatter1D & operator*() { return *_persistent; }
 
     const YODA::Scatter1D & operator*() const { return *_persistent; }
 
     protected:
     vector<YODA::Scatter1DPtr> _persistent;
     };
 
     class Scatter2DPtr : public AnalysisObjectPtr {
     public:
     Scatter2DPtr(size_t len_of_weightvec, const YODA::Scatter2D& p) {
     for (size_t m = 0; m < len_of_weightvec; ++m)
     _persistent.push_back(make_shared<YODA::Scatter2D>(p));
     }
 
     Scatter2DPtr() : _persistent() { }
 
     bool operator!() { return !_persistent; }
     explicit operator bool() { return bool(_persistent); }
 
     YODA::Scatter2D* operator->() { return _persistent.get(); }
 
     YODA::Scatter2D* operator->() const { return _persistent.get(); }
 
     YODA::Scatter2D & operator*() { return *_persistent; }
 
     const YODA::Scatter2D & operator*() const { return *_persistent; }
 
     protected:
     vector<YODA::Scatter2DPtr> _persistent;
     };
 
     class Scatter3DPtr : public AnalysisObjectPtr {
     public:
     Scatter3DPtr(size_t len_of_weightvec, const YODA::Scatter3D& p) {
     for (size_t m = 0; m < len_of_weightvec; ++m)
     _persistent.push_back(make_shared<YODA::Scatter3D>(p));
     }
 
     Scatter3DPtr() : _persistent() { }
 
     bool operator!() { return !_persistent; }
     explicit operator bool() { return bool(_persistent); }
 
     YODA::Scatter3D* operator->() { return _persistent.get(); }
 
     YODA::Scatter3D* operator->() const { return _persistent.get(); }
 
     YODA::Scatter3D & operator*() { return *_persistent; }
 
     const YODA::Scatter3D & operator*() const { return *_persistent; }
 
     protected:
     vector<YODA::Scatter3DPtr> _persistent;
     };
   */
 
 
   class MultiweightAOWrapper : public AnalysisObjectWrapper {
 
   public:
     using Inner = YODA::AnalysisObject;
 
     virtual void newSubEvent() = 0;
 
     virtual void pushToPersistent(const vector<std::valarray<double> >& weight) = 0;
     virtual void pushToFinal() = 0;
 
     virtual YODA::AnalysisObjectPtr activeYODAPtr() const = 0;
 
     virtual string basePath() const = 0;
   };
 
 
   using Weight = double;
 
   template <class T>
   using Fill = pair<typename T::FillType, Weight>;
 
   template <class T>
   using Fills = multiset<Fill<T>>;
 
 
   // TODO TODO TODO
   // need to override the old fill method too!
   // otherwise we can't intercept existing fill calls in analysis code
   // TODO TODO TODO
 
 
   /// Wrappers for analysis objects to store all fills unaggregated, until collapsed
   template <class T>
   class TupleWrapper;
 
   template<>
   class TupleWrapper<YODA::Counter> : public YODA::Counter {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Counter>> Ptr;
     TupleWrapper(const YODA::Counter & h) : YODA::Counter(h) {}
     // todo: do we need to deal with users using fractions directly?
     void fill( double weight=1.0, double fraction=1.0 ) {
       fills_.insert( {YODA::Counter::FillType(),weight} );
     }
     void reset() { fills_.clear(); }
     const Fills<YODA::Counter> & fills() const { return fills_; }
   private:
     // x / weight pairs
     Fills<YODA::Counter> fills_;
   };
 
   template<>
   class TupleWrapper<YODA::Histo1D> : public YODA::Histo1D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Histo1D>> Ptr;
     TupleWrapper(const YODA::Histo1D & h) : YODA::Histo1D(h) {}
     // todo: do we need to deal with users using fractions directly?
     void fill( double x, double weight=1.0, double fraction=1.0 ) {
       if ( std::isnan(x) ) throw YODA::RangeError("X is NaN");
       fills_.insert( { x , weight } );
     }
     void reset() { fills_.clear(); }
     const Fills<YODA::Histo1D> & fills() const { return fills_; }
   private:
     // x / weight pairs
     Fills<YODA::Histo1D> fills_;
   };
 
   template<>
   class TupleWrapper<YODA::Profile1D> : public YODA::Profile1D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Profile1D>> Ptr;
     TupleWrapper(const YODA::Profile1D & h) : YODA::Profile1D(h) {}
     // todo: do we need to deal with users using fractions directly?
     void fill( double x, double y, double weight=1.0, double fraction=1.0 ) {
       if ( std::isnan(x) ) throw YODA::RangeError("X is NaN");
       if ( std::isnan(y) ) throw YODA::RangeError("Y is NaN");
       fills_.insert( { YODA::Profile1D::FillType{x,y}, weight } );
     }
     void reset() { fills_.clear(); }
     const Fills<YODA::Profile1D> & fills() const { return fills_; }
   private:
     // x / weight pairs
     Fills<YODA::Profile1D> fills_;
   };
 
 
   template<>
   class TupleWrapper<YODA::Histo2D> : public YODA::Histo2D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Histo2D>> Ptr;
     TupleWrapper(const YODA::Histo2D & h) : YODA::Histo2D(h) {}
     // todo: do we need to deal with users using fractions directly?
     void fill( double x, double y, double weight=1.0, double fraction=1.0 ) {
       if ( std::isnan(x) ) throw YODA::RangeError("X is NaN");
       if ( std::isnan(y) ) throw YODA::RangeError("Y is NaN");
       fills_.insert( { YODA::Histo2D::FillType{x,y}, weight } );
     }
     void reset() { fills_.clear(); }
     const Fills<YODA::Histo2D> & fills() const { return fills_; }
   private:
     // x / weight pairs
     Fills<YODA::Histo2D> fills_;
   };
 
   template<>
   class TupleWrapper<YODA::Profile2D> : public YODA::Profile2D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Profile2D>> Ptr;
     TupleWrapper(const YODA::Profile2D & h) : YODA::Profile2D(h) {}
     // todo: do we need to deal with users using fractions directly?
     void fill( double x, double y, double z, double weight=1.0, double fraction=1.0 ) {
       if ( std::isnan(x) ) throw YODA::RangeError("X is NaN");
       if ( std::isnan(y) ) throw YODA::RangeError("Y is NaN");
       if ( std::isnan(z) ) throw YODA::RangeError("Z is NaN");
       fills_.insert( { YODA::Profile2D::FillType{x,y,z}, weight } );
     }
     void reset() { fills_.clear(); }
     const Fills<YODA::Profile2D> & fills() const { return fills_; }
   private:
     // x / weight pairs
     Fills<YODA::Profile2D> fills_;
   };
 
   template<>
   class TupleWrapper<YODA::Scatter1D> : public YODA::Scatter1D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Scatter1D>> Ptr;
     TupleWrapper(const YODA::Scatter1D & h) : YODA::Scatter1D(h) {}
   };
 
   template<>
   class TupleWrapper<YODA::Scatter2D> : public YODA::Scatter2D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Scatter2D>> Ptr;
     TupleWrapper(const YODA::Scatter2D & h) : YODA::Scatter2D(h) {}
   };
 
   template<>
   class TupleWrapper<YODA::Scatter3D> : public YODA::Scatter3D {
   public:
     typedef shared_ptr<TupleWrapper<YODA::Scatter3D>> Ptr;
     TupleWrapper(const YODA::Scatter3D & h) : YODA::Scatter3D(h) {}
   };
 
 
 
   template <class T>
   class Wrapper : public MultiweightAOWrapper {
     friend class Analysis;
 
   public:
 
     using Inner = T;
     /* @todo
      * some things are not really well-defined here
      * for instance: fill() in the finalize() method and integral() in
      * the analyze() method.
      */
 
     Wrapper() = default;
 
     Wrapper(const vector<string>& weightnames, const T & p);
 
     ~Wrapper();
 
     typename T::Ptr active() const;
 
     /* @todo this probably need to loop over all? */
     bool operator!() const { return !_active; } // Don't use active() here, assert will catch
 
     explicit operator bool() const { return static_cast<bool>(_active); } // Don't use active() here, assert will catch
 
     T * operator->() { return active().get(); }
 
     T * operator->() const { return active().get(); }
 
     T & operator*() { return *active(); }
 
     const T & operator*() const { return *active(); }
 
     // can be useful for weight analysis (see e.g. MC_WEIGHTS for use)
     T * _getPersistent (unsigned int iWeight) { return _persistent.at(iWeight).get(); } 
 
 
     /* @todo
      * these need to be re-thought out.
 
      void reset() { active()->reset(); }
     */
 
     /* @todo
      * these probably need to loop over all?
      * do we even want to provide equality?
      */
     /* @todo
      * how about no.
      friend bool operator==(Wrapper a, Wrapper b){
      if (a._persistent.size() != b._persistent.size())
      return false;
 
      for (size_t i = 0; i < a._persistent.size(); i++) {
      if (a._persistent.at(i) != b._persistent.at(i)) {
      return false;
      }
      }
 
      return true;
      }
 
      friend bool operator!=(Wrapper a, Wrapper b){
      return !(a == b);
      }
 
 
      friend bool operator<(Wrapper a, Wrapper b){
      if (a._persistent.size() >= b._persistent.size())
      return false;
 
      for (size_t i = 0; i < a._persistent.size(); i++) {
      if (*(a._persistent.at(i)) >= *(b._persistent.at(i))) {
      return false;
      }
      }
 
      return true;
      }
     */
 
 
   private:
     void setActiveWeightIdx(unsigned int iWeight) {
       _active = _persistent.at(iWeight);
     }
 
     void setActiveFinalWeightIdx(unsigned int iWeight) {
       _active = _final.at(iWeight);
     }
 
 
     /* this is for dev only---we shouldn't need this in real runs. */
     void unsetActiveWeight() { _active.reset(); }
 
     void newSubEvent();
 
     virtual YODA::AnalysisObjectPtr activeYODAPtr() const { return _active; }
 
     const vector<typename T::Ptr> & persistent() const { return _persistent; }
 
     const vector<typename T::Ptr> & final() const { return _final; }
 
     /* to be implemented for each type */
     void pushToPersistent(const vector<std::valarray<double> >& weight);
     void pushToFinal();
 
 
     /* M of these, one for each weight */
     vector<typename T::Ptr> _persistent;
 
     /* This is the copy of _persistent that will be passed to finalize(). */
     vector<typename T::Ptr> _final;
 
     /* N of these, one for each event in evgroup */
     vector<typename TupleWrapper<T>::Ptr> _evgroup;
 
     typename T::Ptr _active;
 
     string basePath() const { return _basePath; }
 
     string _basePath;
 
     // do we need implicit cast?
     // operator typename T::Ptr () {
     //     return _active;
     // }
 
     friend class AnalysisHandler;
   };
 
 
   /// We need our own shared_ptr class, so we can dispatch -> and *
   /// all the way down to the inner YODA analysis objects
   ///
   /// TODO: provide remaining functionality that shared_ptr has (not needed right now)
   ///
   template <typename T>
   class rivet_shared_ptr {
   public:
     typedef T value_type;
 
     rivet_shared_ptr() = default;
 
     rivet_shared_ptr(decltype(nullptr)) : _p(nullptr) {}
 
     /// Convenience constructor, pass through to the Wrapper constructor
     rivet_shared_ptr(const vector<string>& weightNames, const typename T::Inner & p)
       : _p( make_shared<T>(weightNames, p) )
     {}
 
     template <typename U>
     rivet_shared_ptr(const shared_ptr<U> & p)
       : _p(p)
     {}
 
     template <typename U>
     rivet_shared_ptr(const rivet_shared_ptr<U> & p)
       : _p(p.get())
     {}
 
-    // Goes right through to the active YODA object's members
+    // Goes right through to the active Wrapper<YODA> object's members
     T & operator->()                            { return  *_p; }
     const T & operator->() const                { return  *_p; }
 
     // The active YODA object
     typename T::Inner & operator*()             { return **_p; }
     const typename T::Inner & operator*() const { return **_p; }
 
     bool operator!() const { return !_p || !(*_p);   }
     explicit operator bool()  const { return _p && bool(*_p); }
 
     template <typename U>
     bool operator==(const rivet_shared_ptr<U> & other) const {
       return _p == other._p;
     }
 
     template <typename U>
     bool operator!=(const rivet_shared_ptr<U> & other) const {
       return _p != other._p;
     }
 
     template <typename U>
     bool operator<(const rivet_shared_ptr<U> & other) const {
       return _p < other._p;
     }
 
     template <typename U>
     bool operator>(const rivet_shared_ptr<U> & other) const {
       return _p > other._p;
     }
 
     template <typename U>
     bool operator<=(const rivet_shared_ptr<U> & other) const {
       return _p <= other._p;
     }
 
     template <typename U>
     bool operator>=(const rivet_shared_ptr<U> & other) const {
       return _p >= other._p;
     }
 
     shared_ptr<T> get() const { return _p; }
 
   private:
     shared_ptr<T> _p;
 
   };
 
 
 
   // every object listed here needs a virtual fill method in YODA,
   // otherwise the Tuple fakery won't work.
 
   using MultiweightAOPtr = rivet_shared_ptr<MultiweightAOWrapper>;
 
   using Histo1DPtr   = rivet_shared_ptr<Wrapper<YODA::Histo1D>>;
   using Histo2DPtr   = rivet_shared_ptr<Wrapper<YODA::Histo2D>>;
   using Profile1DPtr = rivet_shared_ptr<Wrapper<YODA::Profile1D>>;
   using Profile2DPtr = rivet_shared_ptr<Wrapper<YODA::Profile2D>>;
   using CounterPtr   = rivet_shared_ptr<Wrapper<YODA::Counter>>;
   using Scatter1DPtr = rivet_shared_ptr<Wrapper<YODA::Scatter1D>>;
   using Scatter2DPtr = rivet_shared_ptr<Wrapper<YODA::Scatter2D>>;
   using Scatter3DPtr = rivet_shared_ptr<Wrapper<YODA::Scatter3D>>;
 
   using YODA::Counter;
   using YODA::Histo1D;
   using YODA::HistoBin1D;
   using YODA::Histo2D;
   using YODA::HistoBin2D;
   using YODA::Profile1D;
   using YODA::ProfileBin1D;
   using YODA::Profile2D;
   using YODA::ProfileBin2D;
   using YODA::Scatter1D;
   using YODA::Point1D;
   using YODA::Scatter2D;
   using YODA::Point2D;
   using YODA::Scatter3D;
   using YODA::Point3D;
 
   /// Function to get a map of all the refdata in a paper with the
   /// given @a papername.
   map<string, YODA::AnalysisObjectPtr> getRefData(const string& papername);
 
   /// @todo Also provide a Scatter3D getRefData() version?
 
   /// Get the file system path to the reference file for this paper.
   string getDatafilePath(const string& papername);
 
 
   /// Traits class to access the type of the AnalysisObject in the
   /// reference files.
   template<typename T> struct ReferenceTraits {};
   template<> struct ReferenceTraits<Counter> { typedef Counter RefT; };
   template<> struct ReferenceTraits<Scatter1D> { typedef Scatter1D RefT; };
   template<> struct ReferenceTraits<Histo1D> { typedef Scatter2D RefT; };
   template<> struct ReferenceTraits<Profile1D> { typedef Scatter2D RefT; };
   template<> struct ReferenceTraits<Scatter2D> { typedef Scatter2D RefT; };
   template<> struct ReferenceTraits<Histo2D> { typedef Scatter3D RefT; };
   template<> struct ReferenceTraits<Profile2D> { typedef Scatter3D RefT; };
   template<> struct ReferenceTraits<Scatter3D> { typedef Scatter3D RefT; };
 
 
   /// If @a dst and @a src both are of same subclass T, copy the
   /// contents of @a src into @a dst and return true. Otherwise return
   /// false.
   template <typename T>
   inline bool aocopy(YODA::AnalysisObjectPtr src, YODA::AnalysisObjectPtr dst) {
     shared_ptr<T> tsrc = dynamic_pointer_cast<T>(src);
     if ( !tsrc ) return false;
     shared_ptr<T> tdst = dynamic_pointer_cast<T>(dst);
     if ( !tdst ) return false;
     *tdst = *tsrc;
     return true;
   }
 
   /// If @a dst and @a src both are of same subclass T, add the
   /// contents of @a src into @a dst and return true. Otherwise return
   /// false.
   template <typename T>
   inline bool aoadd(YODA::AnalysisObjectPtr dst, YODA::AnalysisObjectPtr src, double scale) {
     shared_ptr<T> tsrc = dynamic_pointer_cast<T>(src);
     if ( !tsrc ) return false;
     shared_ptr<T> tdst = dynamic_pointer_cast<T>(dst);
     if ( !tdst ) return false;
     tsrc->scaleW(scale);
     *tdst += *tsrc;
     return true;
   }
 
   /// If @a dst is the same subclass as @a src, copy the contents of @a
   /// src into @a dst and return true. Otherwise return false.
   bool copyao(YODA::AnalysisObjectPtr src, YODA::AnalysisObjectPtr dst);
 
   /// If @a dst is the same subclass as @a src, scale the contents of
   /// @a src with @a scale and add it to @a dst and return true. Otherwise
   /// return false.
   bool addaos(YODA::AnalysisObjectPtr dst, YODA::AnalysisObjectPtr src, double scale);
 
   /// Check if two analysis objects have the same binning or, if not
   /// binned, are in other ways compatible.
   template <typename TPtr>
   inline bool bookingCompatible(TPtr a, TPtr b) {
     return a->sameBinning(*b);
   }
   inline bool bookingCompatible(CounterPtr, CounterPtr) {
     return true;
   }
   inline bool bookingCompatible(Scatter1DPtr a, Scatter1DPtr b) {
     return a->numPoints() == b->numPoints();
   }
   inline bool bookingCompatible(Scatter2DPtr a, Scatter2DPtr b) {
     return a->numPoints() == b->numPoints();
   }
   inline bool bookingCompatible(Scatter3DPtr a, Scatter3DPtr b) {
     return a->numPoints() == b->numPoints();
   }
   inline bool bookingCompatible(YODA::CounterPtr, YODA::CounterPtr) {
     return true;
   }
   inline bool bookingCompatible(YODA::Scatter1DPtr a, YODA::Scatter1DPtr b) {
     return a->numPoints() == b->numPoints();
   }
   inline bool bookingCompatible(YODA::Scatter2DPtr a, YODA::Scatter2DPtr b) {
     return a->numPoints() == b->numPoints();
   }
   inline bool bookingCompatible(YODA::Scatter3DPtr a, YODA::Scatter3DPtr b) {
     return a->numPoints() == b->numPoints();
   }
 
   /// class representing a YODA path with all its components.
 class AOPath {
 
   public:
 
     /// Constructor
     AOPath(string fullpath)
       : _valid(false), _path(fullpath), _raw(false), _tmp(false), _ref(false) {
       _valid = init(fullpath);
     }
 
     /// The full path.
     string path() const { return _path; }
 
     /// The analysis name.
     string analysis() const { return _analysis; }
 
     /// The analysis name with options.
     string analysisWithOptions() const { return _analysis + _optionstring; }
 
     /// The base name of the analysis object.
     string name() const { return _name; }
 
     /// The weight name.
     string weight() const { return _weight; }
 
     /// Is This a RAW (filling) object?
     bool   isRaw() const { return _raw; }
 
     // Is This a temporary (filling) object?
     bool   isTmp() const { return _tmp; }
 
     /// Is This a reference object?
     bool   isRef() const { return _ref; }
 
     /// The string describing the options passed to the analysis.
     string optionString() const { return _optionstring; }
 
     /// Are there options passed to the analysis?
     bool   hasOptions() const { return !_options.empty(); }
 
     /// Don't pass This optionto the analysis
     void   removeOption(string opt) { _options.erase(opt); fixOptionString(); }
 
     /// Pass this option to the analysis.
     void   setOption(string opt, string val) { _options[opt] = val; fixOptionString();}
 
     /// Was This option passed to the analyisi.
     bool   hasOption(string opt) const { return _options.find(opt) != _options.end(); }
 
     /// Get the value of this option.
     string getOption(string opt) const {
       auto it = _options.find(opt);
       if ( it != _options.end() ) return it->second;
       return "";
     }
 
     /// Reset the option string after changes;
     void fixOptionString();
 
     /// Creat a full path (and set) for this.
     string mkPath() const;
     string setPath() { return _path = mkPath(); }
 
     /// Print out information
     void debug() const;
 
     /// Make this class ordered.
     bool operator<(const AOPath & other) const {
       return _path < other._path;
     }
 
     /// Check if path is valid.
     bool valid() const { return _valid; };
     bool operator!() const { return !valid(); }
 
   private:
 
     /// Internal functions for disassembling a path name
     bool init(string fullpath);
     bool chopweight(string & fullpath);
     bool chopoptions(string & anal);
 
     bool _valid;
     string _path;
     string _analysis;
     string _optionstring;
     string _name;
     string _weight;
     bool _raw;
     bool _tmp;
     bool _ref;
     map<string,string> _options;
 
   };
 
 }
 
 #endif
diff --git a/src/Tools/RivetYODA.cc b/src/Tools/RivetYODA.cc
--- a/src/Tools/RivetYODA.cc
+++ b/src/Tools/RivetYODA.cc
@@ -1,571 +1,571 @@
 #include "Rivet/Config/RivetCommon.hh"
 #include "Rivet/Tools/RivetYODA.hh"
 #include "Rivet/Tools/RivetPaths.hh"
 #include "YODA/ReaderYODA.h"
 #include "YODA/ReaderAIDA.h"
 
 // use execinfo for backtrace if available
 #include "DummyConfig.hh"
 #ifdef HAVE_EXECINFO_H
 #include <execinfo.h>
 #endif
 
 // #include <regex>
 #include <sstream>
 
 using namespace std;
 
 namespace Rivet {
 
 
 template <class T>
 Wrapper<T>::~Wrapper() {}
 
 
 template <class T>
 Wrapper<T>::Wrapper(const vector<string>& weightNames, const T & p)
 {
   _basePath = p.path();
   for (const string& weightname : weightNames) {
     _persistent.push_back(make_shared<T>(p));
     _final.push_back(make_shared<T>(p));
 
     auto obj = _persistent.back();
     obj->setPath("/RAW" + obj->path());
     auto final = _final.back();
     if (weightname != "") {
       obj->setPath(obj->path() + "[" + weightname + "]");
       final->setPath(final->path() + "[" + weightname + "]");
     }
   }
 }
 
 
 template <class T>
 typename T::Ptr Wrapper<T>::active() const {
     if ( !_active ) {
 #ifdef HAVE_BACKTRACE
       void * buffer[4];
       backtrace(buffer, 4);
       backtrace_symbols_fd(buffer, 4 , 1);
 #endif
       assert(false && "No active pointer set. Was this object booked in init()?");
     }
     return _active;
 }
 
 
 template <class T>
 void Wrapper<T>::newSubEvent() {
   typename TupleWrapper<T>::Ptr tmp
       = make_shared<TupleWrapper<T>>(_persistent[0]->clone());
   tmp->reset();
   _evgroup.push_back( tmp );
   _active = _evgroup.back();
   assert(_active);
 }
 
 
 
   string getDatafilePath(const string& papername) {
     /// Try to find YODA otherwise fall back to try AIDA
     const string path1 = findAnalysisRefFile(papername + ".yoda");
     if (!path1.empty()) return path1;
     const string path2 = findAnalysisRefFile(papername + ".aida");
     if (!path2.empty()) return path2;
     throw Rivet::Error("Couldn't find ref data file '" + papername + ".yoda" +
                        " in data path, '" + getRivetDataPath() + "', or '.'");
   }
 
 
   map<string, YODA::AnalysisObjectPtr> getRefData(const string& papername) {
     const string datafile = getDatafilePath(papername);
 
     // Make an appropriate data file reader and read the data objects
     /// @todo Remove AIDA support some day...
     YODA::Reader& reader = (datafile.find(".yoda") != string::npos) ?   \
       YODA::ReaderYODA::create() : YODA::ReaderAIDA::create();
     vector<YODA::AnalysisObject *> aovec;
     reader.read(datafile, aovec);
 
     // Return value, to be populated
     map<string, YODA::AnalysisObjectPtr> rtn;
     for ( YODA::AnalysisObject* ao : aovec ) {
       YODA::AnalysisObjectPtr refdata(ao);
       if (!refdata) continue;
       const string plotpath = refdata->path();
       // Split path at "/" and only return the last field, i.e. the histogram ID
       const size_t slashpos = plotpath.rfind("/");
       const string plotname = (slashpos+1 < plotpath.size()) ? plotpath.substr(slashpos+1) : "";
       rtn[plotname] = refdata;
     }
     return rtn;
   }
 
 
 }
 
 
 namespace {
 
   using Rivet::Fill;
   using Rivet::Fills;
   using Rivet::TupleWrapper;
 
     template <class T>
     double get_window_size(const typename T::Ptr & histo,
                            typename T::BinType x) {
         // the bin index we fall in
         const auto binidx = histo->binIndexAt(x);
         // gaps, overflow, underflow don't contribute
         if ( binidx == -1 )
             return 0;
 
 
         const auto & b = histo->bin(binidx);
 
         // if we don't have a valid neighbouring bin,
         // we use infinite width
         typename T::Bin b1(-1.0/0.0, 1.0/0.0);
 
         // points in the top half compare to the upper neighbour
         if ( x > b.xMid() ) {
             size_t nextidx = binidx + 1;
             if ( nextidx < histo->bins().size() )
                 b1 = histo->bin(nextidx);
         }
         else { // compare to the lower neighbour
             int nextidx = binidx - 1;
             if ( nextidx >= 0 )
                 b1 = histo->bin(nextidx);
         }
         // the factor 2 is arbitrary, could poss. be smaller
         return min( b.width(), b1.width() ) / 2.0;
     }
 
     template <class T>
      typename T::BinType
      fillT2binT(typename T::FillType a) {
        return a;
     }
 
     template <>
     YODA::Profile1D::BinType
     fillT2binT<YODA::Profile1D>(YODA::Profile1D::FillType a) {
       return get<0>(a);
     }
 
     template <>
     YODA::Profile2D::BinType
     fillT2binT<YODA::Profile2D>(YODA::Profile2D::FillType a) {
       return YODA::Profile2D::BinType{ get<0>(a), get<1>(a) };
     }
 
 
 
   template <class T>
   void commit(vector<typename T::Ptr> & persistent,
               const vector< vector<Fill<T>> > & tuple,
               const vector<valarray<double>> & weights ) {
 
     // TODO check if all the xs are in the same bin anyway!
     // Then no windowing needed
 
     assert(persistent.size() == weights[0].size());
 
     for ( const auto & x : tuple ) {
       double maxwindow = 0.0;
       for ( const auto & xi : x ) {
         // TODO check for NOFILL here
         // persistent[0] has the same binning as all the other persistent objects
         double window = get_window_size<T>(persistent[0], fillT2binT<T>(xi.first));
         if ( window > maxwindow )
           maxwindow = window;
       }
       const double wsize = maxwindow;
       // all windows have same size
 
       set<double> edgeset;
       // bin edges need to be in here!
       for ( const auto & xi : x ) {
         edgeset.insert(fillT2binT<T>(xi.first) - wsize);
         edgeset.insert(fillT2binT<T>(xi.first) + wsize);
       }
 
           vector< std::tuple<double,valarray<double>,double> > hfill;
           double sumf = 0.0;
           auto edgit = edgeset.begin();
           double ehi = *edgit;
           while ( ++edgit != edgeset.end() ) {
             double elo = ehi;
             ehi = *edgit;
             valarray<double> sumw(0.0, persistent.size()); // need m copies of this
             bool gap = true; // Check for gaps between the sub-windows.
             for ( size_t i = 0; i < x.size(); ++i  ) {
               // check equals comparisons here!
               if ( fillT2binT<T>(x[i].first) + wsize >= ehi
                    &&
                    fillT2binT<T>(x[i].first) - wsize <= elo ) {
                 sumw += x[i].second * weights[i];
                 gap = false;
               }
             }
             if ( gap ) continue;
             hfill.push_back( make_tuple( (ehi + elo)/2.0, sumw, (ehi - elo) ) );
             sumf += ehi - elo;
           }
 
           for ( auto f : hfill )
             for ( size_t m = 0; m < persistent.size(); ++m )
               persistent[m]->fill( get<0>(f), get<1>(f)[m], get<2>(f)/sumf );
             // Note the scaling to one single fill
 
     }
 
   }
 
 
   template<>
   void commit<YODA::Histo2D>(vector<YODA::Histo2D::Ptr> & persistent,
               const vector< vector<Fill<YODA::Histo2D>> > & tuple,
               const vector<valarray<double>> & weights)
   {}
 
   template<>
   void commit<YODA::Profile2D>(vector<YODA::Profile2D::Ptr> & persistent,
               const vector< vector<Fill<YODA::Profile2D>> > & tuple,
               const vector<valarray<double>> & weights)
   {}
 
     template <class T>
     double distance(T a, T b) {
       return abs(a - b);
     }
 
     template <>
     double distance<tuple<double,double> >(tuple<double,double> a, tuple<double,double> b) {
       return Rivet::sqr(get<0>(a) - get<0>(b)) + Rivet::sqr(get<1>(a) - get<1>(b));
     }
 
   }
 
 
   namespace Rivet {
 
     bool copyao(YODA::AnalysisObjectPtr src, YODA::AnalysisObjectPtr dst) {
       for (const std::string& a : src->annotations())
         dst->setAnnotation(a, src->annotation(a));
       if ( aocopy<Counter>(src,dst) ) return true;
       if ( aocopy<Histo1D>(src,dst) ) return true;
       if ( aocopy<Histo2D>(src,dst) ) return true;
       if ( aocopy<Profile1D>(src,dst) ) return true;
       if ( aocopy<Profile2D>(src,dst) ) return true;
       if ( aocopy<Scatter1D>(src,dst) ) return true;
       if ( aocopy<Scatter2D>(src,dst) ) return true;
       if ( aocopy<Scatter3D>(src,dst) ) return true;
       return false;
     }
 
     bool addaos(YODA::AnalysisObjectPtr dst, YODA::AnalysisObjectPtr src, double scale) {
       if ( aoadd<Counter>(dst,src,scale) ) return true;
       if ( aoadd<Histo1D>(dst,src,scale) ) return true;
       if ( aoadd<Histo2D>(dst,src,scale) ) return true;
       if ( aoadd<Profile1D>(dst,src,scale) ) return true;
       if ( aoadd<Profile2D>(dst,src,scale) ) return true;
       return false;
     }
 
   }
 
 
 namespace {
 
 /// fills is a vector of sub-event with an ordered set of x-values of
 /// the fills in each sub-event. NOFILL should be an "impossible"
 /// value for this histogram. Returns a vector of sub-events with
 /// an ordered vector of fills (including NOFILLs) for each sub-event.
 template <class T>
 vector< vector<Fill<T> > >
 match_fills(const vector<typename TupleWrapper<T>::Ptr> & evgroup, const Fill<T> & NOFILL)
 {
   vector< vector<Fill<T> > > matched;
   // First just copy subevents into vectors and find the longest vector.
   unsigned int maxfill = 0; // length of biggest vector
   int imax = 0; // index position of biggest vector
   for ( const auto & it : evgroup ) {
     const auto & subev = it->fills();
     if ( subev.size() > maxfill ) {
       maxfill = subev.size();
       imax = matched.size();
     }
     matched.push_back(vector<Fill<T> >(subev.begin(), subev.end()));
   }
   // Now, go through all subevents with missing fills.
   const vector<Fill<T>> & full = matched[imax]; // the longest one
   for ( auto & subev : matched ) {
     if ( subev.size() == maxfill ) continue;
 
     // Add NOFILLs to the end;
     while ( subev.size() < maxfill ) subev.push_back(NOFILL);
 
     // Iterate from the back and shift all fill values backwards by
     // swapping with NOFILLs so that they better match the full
     // subevent.
     for ( int i = maxfill - 1; i >= 0; --i ) {
       if ( subev[i] == NOFILL ) continue;
       size_t j = i;
       while ( j + 1 < maxfill && subev[j + 1] == NOFILL &&
               distance(fillT2binT<T>(subev[j].first),
                        fillT2binT<T>(full[j].first))
               >
               distance(fillT2binT<T>(subev[j].first),
                        fillT2binT<T>(full[j + 1].first)) )
       {
             swap(subev[j], subev[j + 1]);
             ++j;
       }
     }
   }
   // transpose
   vector<vector<Fill<T>>> result(maxfill,vector<Fill<T>>(matched.size()));
   for (size_t i = 0; i < matched.size(); ++i)
       for (size_t j = 0; j < maxfill; ++j)
           result.at(j).at(i) = matched.at(i).at(j);
   return result;
 }
 
 }
 
 
 
 
 namespace Rivet {
 
   template <class T>
   void Wrapper<T>::pushToPersistent(const vector<valarray<double> >& weight) {
       assert( _evgroup.size() == weight.size() );
 
       // have we had subevents at all?
       const bool have_subevents = _evgroup.size() > 1;
       if ( ! have_subevents ) {
 
 
 
         // simple replay of all tuple entries
         // each recorded fill is inserted into all persistent weightname histos
-        for ( size_t m = 0; m < _persistent.size(); ++m )
+        for ( size_t m = 0; m < _persistent.size(); ++m ) //< m is the variation index
             for ( const auto & f : _evgroup[0]->fills() )
                 _persistent[m]->fill( f.first, f.second * weight[0][m] );
 
 
 
       } else {
 
 
 
         // outer index is subevent, inner index is jets in the event
         vector<vector<Fill<T>>> linedUpXs
             = match_fills<T>(_evgroup, {typename T::FillType(), 0.0});
         commit<T>( _persistent, linedUpXs, weight );
 
 
 
       }
       _evgroup.clear();
       _active.reset();
   }
 
   template <class T>
   void Wrapper<T>::pushToFinal() {
     for ( size_t m = 0; m < _persistent.size(); ++m ) {
       copyao(_persistent.at(m), _final.at(m));
       if ( _final[m]->path().substr(0,4) == "/RAW" )
         _final[m]->setPath(_final[m]->path().substr(4));
     }
   }
 
 
 
   template <>
   void Wrapper<YODA::Counter>::pushToPersistent(const vector<valarray<double> >& weight) {
     for ( size_t m = 0; m < _persistent.size(); ++m ) {
       for ( size_t n = 0; n < _evgroup.size(); ++n ) {
         for ( const auto & f : _evgroup[n]->fills() ) {
           _persistent[m]->fill( f.second * weight[n][m] );
         }
       }
     }
 
     _evgroup.clear();
     _active.reset();
   }
 
   template <>
   void Wrapper<YODA::Scatter1D>::pushToPersistent(const vector<valarray<double> >& weight) {
 
     _evgroup.clear();
     _active.reset();
   }
 
   template <>
   void Wrapper<YODA::Scatter2D>::pushToPersistent(const vector<valarray<double> >& weight) {
 
     _evgroup.clear();
     _active.reset();
   }
 
   template <>
   void Wrapper<YODA::Scatter3D>::pushToPersistent(const vector<valarray<double> >& weight) {
 
     _evgroup.clear();
     _active.reset();
   }
 
   // explicitly instantiate all wrappers
 
   template class Wrapper<YODA::Histo1D>;
   template class Wrapper<YODA::Histo2D>;
   template class Wrapper<YODA::Profile1D>;
   template class Wrapper<YODA::Profile2D>;
   template class Wrapper<YODA::Counter>;
   template class Wrapper<YODA::Scatter1D>;
   template class Wrapper<YODA::Scatter2D>;
   template class Wrapper<YODA::Scatter3D>;
 
 
   /// Possible future solution based on regex
   /*
   AOPath::AOPath(string fullpath) {
     // First check if this is a global system path
     _path = fullpath;
     std::regex resys("^(/RAW)?/([^\\[/]+)(\\[(.+)\\])?$");
     smatch m;
     _valid = regex_search(fullpath, m, resys);
     if ( _valid ) {
       _raw = (m[1] == "/RAW");
       _name = m[2];
       _weight = m[4];
       return;
     }
     // If not, assume it is a normal analysis path.
     std::regex repath("^(/RAW)?(/REF)?/([^/:]+)(:[^/]+)?(/TMP)?/([^\\[]+)(\\[(.+)\\])?");
     _valid = regex_search(fullpath, m, repath);
-    if ( !_valid ) return;     
+    if ( !_valid ) return;
     _raw = (m[1] == "/RAW");
     _ref = (m[2] == "/REF");
     _analysis = m[3];
     _optionstring = m[4];
     _tmp = (m[5] == "/TMP");
     _name = m[6];
     _weight = m[8];
     std::regex reopt(":([^=]+)=([^:]+)");
     string s = _optionstring;
     while ( regex_search(s, m, reopt) ) {
       _options[m[1]] = m[2];
       s = m.suffix();
     }
   }
   */
 
   bool AOPath::init(string fullpath) {
     if ( fullpath.substr(0,5) == "/RAW/" ) {
       _raw = true;
       return init(fullpath.substr(4));
     }
     if ( fullpath.substr(0,5) == "/REF/" ) {
       _ref = true;
       return init(fullpath.substr(4));
     }
     if ( fullpath[0] != '/' ) return false;
 
     fullpath = fullpath.substr(1);
 
     if ( fullpath.size() < 2 ) return false;
 
     if ( !chopweight(fullpath) ) return false;
-    
+
     string::size_type p = fullpath.find("/");
     if ( p == 0 ) return false;
     if ( p == string::npos ) {
       _name = fullpath;
       return true;
     }
     _analysis = fullpath.substr(0, p);
     _name = fullpath.substr(p + 1);
 
     if ( _name.substr(0, 4) == "TMP/" ) {
       _name = _name.substr(4);
       _tmp = true;
     }
 
     if ( !chopoptions(_analysis) ) return false;
 
     fixOptionString();
 
     return true;
   }
 
   bool AOPath::chopweight(string & fullpath) {
     if ( fullpath.back() != ']' ) return true;
     string::size_type p = fullpath.rfind("[");
     if ( p == string::npos ) return false;
     _weight = fullpath.substr(p + 1);
     _weight.pop_back();
     fullpath = fullpath.substr(0, p);
     return true;
   }
 
   bool AOPath::chopoptions(string & anal) {
     string::size_type p = anal.rfind(":");
     if ( p == string::npos ) return true;
     string opts = anal.substr(p + 1);
     string::size_type pp = opts.find("=");
     if ( pp == string::npos ) return false;
     _options[opts.substr(0, pp)] = opts.substr(pp + 1);
     anal = anal.substr(0, p);
     return chopoptions(anal);
   }
-    
+
   void AOPath::fixOptionString() {
     ostringstream oss;
     for ( auto optval : _options )
       oss << ":" << optval.first << "=" << optval.second;
     _optionstring = oss.str();
   }
 
   string AOPath::mkPath() const {
     ostringstream oss;
     if ( isRaw() ) oss << "/RAW";
     else if ( isRef() ) oss << "/REF";
     if ( _analysis != "" ) oss << "/" << analysis();
     for ( auto optval : _options )
       oss << ":" << optval.first << "=" << optval.second;
     if ( isTmp() ) oss << "/TMP";
     oss << "/" << name();
     if ( weight() != "" )
       oss << "[" << weight() << "]";
     return oss.str();
   }
 
   void AOPath::debug() const {
     cout << "Full path:  " << _path << endl;
     if ( !_valid ) {
       cout << "This is not a valid analysis object path" << endl << endl;
       return;
     }
     cout << "Check path: " << mkPath() << endl;
     cout << "Analysis:   " << _analysis << endl;
     cout << "Name:       " << _name << endl;
     cout << "Weight:     " << _weight << endl;
     cout << "Properties: ";
     if ( _raw ) cout << "raw ";
     if ( _tmp ) cout << "tmp ";
     if ( _ref ) cout << "ref ";
     cout << endl;
     cout << "Options:    ";
     for ( auto opt : _options )
       cout << opt.first << "->" << opt.second << " ";
     cout << endl << endl;
   }
 
 }