TCutG

class TCutG : public TGraph

    public:

                      TCutG TCutG()
                      TCutG TCutG(Text_t* name, Int_t n, Float_t* x = 0, Float_t* y = 0)
                      TCutG TCutG(TCutG&)
               virtual void ~TCutG()
                    TClass* Class()
           virtual Double_t EvalInstance(Int_t instance)
      virtual const Text_t* GetVarX()
      virtual const Text_t* GetVarY()
            virtual TClass* IsA()
              virtual Int_t IsInside(Float_t x, Float_t y)
               virtual void SavePrimitive(ofstream& out, Option_t* option)
               virtual void SetTree(TTree* tree)
               virtual void SetVarX(Text_t* varx)
               virtual void SetVarY(Text_t* vary)
               virtual void ShowMembers(TMemberInspector& insp, char* parent)
               virtual void Streamer(TBuffer& b)

  Data Members

    protected:

            TString fVarX      X variable
            TString fVarY      Y variable
      TTreeFormula* fFormulaX  !pointer to TreeFormula for X
      TTreeFormula* fFormulaY  !pointer to TreeFormula for Y
             TTree* fTree      !pointer to current tree

Class Description

                                                                      
 TCutG                                                                
                                                                      
  A Graphical cut.                                                    
  A TCutG object defines a closed polygon in a x,y plot.              
  It can be created via the graphics editor option "CutG"             
  or directly by invoking its constructor.                            
  When it is created via the graphics editor, the TCutG object        
  is named "CUTG". It is recommended to immediatly change the name    
  by using the context menu item "SetName".                           //                                                                      
   When the graphics editor is used, the names of the variables X,Y   
   are automatically taken from the current pad title.                
  Example:                                                            
  Assume a TTree object T and:                                        
     Root > T.Draw("abs(fMomemtum)%fEtot")                            
  the TCutG members fVarX, fVary will be set to:                      
     fVarx = fEtot                                                    
     fVary = abs(fMomemtum)                                           
                                                                      
  A graphical cut can be used in a TTree selection expression:        
    Root > T.Draw("fEtot","cutg1")                                    
    where "cutg1" is the name of an existing graphical cut.           
                                                                      
  Note that, as shown in the example above, a graphical cut may be    
  used in a selection expression when drawing TTrees expressions      
  of 1-d, 2-d or 3-dimensions.                                        
  The TTree expressions may or may not reference the same variables   
  than in the fVarX, fVarY of the graphical cut.                      
                                                                      
  When the TCutG object is created via the graphics editor, it is     
  added to the list of primitives in the pointed pad. To retrieve     
  a pointer to this object from the code or command line, do:         
      TCutG *mycutg = (TCutG*)gPad->GetPrimitive("CUTG");             
      mycutg->SetName("mycutg");                                      
                                                                      
  A Graphical cut may be drawn via TGraph::Draw.                      
  It can be edited like a normal TGraph.                              
                                                                      
  A Graphical cut may be saved to a file via TCutG::Write.            //                                                                     
                                                                      
  A TCutG object is added in the gROOT->GetListOfSpecials             
                                                                      

  Evaluate graphical cut value for current entry instance

*.         Function which returns 1 if point x,y lies inside the
*.              polygon defined by the graph points
*.                                0 otherwise
*.
*.     The loop is executed with the end-point coordinates of a
*.     line segment (X1,Y1)-(X2,Y2) and the Y-coordinate of a
*.     horizontal line.
*.     The counter inter is incremented if the line (X1,Y1)-(X2,Y2)
*.     intersects the horizontal line.
*.     In this case XINT is set to the X-coordinate of the
*.     intersection point.
*.     If inter is an odd number, then the point x,y is not within
*.     the polygon.
*.
*.         This routine is based on an original algorithm
*.         developed by R.Nierhaus.
*.

 Save primitive as a C++ statement(s) on output stream out

Inline Functions

        const Text_t* GetVarX()
        const Text_t* GetVarY()
                 void SetTree(TTree* tree)
              TClass* Class()
              TClass* IsA()
                 void ShowMembers(TMemberInspector& insp, char* parent)
                 void Streamer(TBuffer& b)
                TCutG TCutG(TCutG&)