First attempt to introduce the new class TGraph2D( from Olivier).

This class is a set of N points x[i],y[i],zi[i] in a non uniform grid.
Several visualisation techniques are implemented, includind Delaunay triangulation.
This new class is great and an important addition to ROOT.


git-svn-id: http://root.cern.ch/svn/root/trunk@7484 27541ba8-7e3a-0410-8455-c3a389f83636

graf/inc/LinkDef2.h

-/* @(#)root/graf:$Name:  $:$Id: LinkDef2.h,v 1.4 2002/08/09 13:56:00 rdm Exp $ */
+/* @(#)root/graf:$Name:  $:$Id: LinkDef2.h,v 1.5 2003/01/22 11:23:03 rdm Exp $ */
 
 /*************************************************************************
  * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
@@ -14,6 +14,7 @@
 #pragma link off all classes;
 #pragma link off all functions;
 
+#pragma link C++ class TGraph2D+;
 #pragma link C++ class TGraphSmooth+;
 #pragma link C++ class TLatex+;
 #pragma link C++ class TLegend+;

graf/inc/TGraph2D.h

+// @(#)root/graf:$Name:  $:$Id: TGraph2D.h,v 1.00
+// Author: Olivier Couet   23/10/03
+// Author: Luke Jones (Royal Holloway, University of London) April 2002
+
+/*************************************************************************
+ * 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.             *
+ *************************************************************************/
+
+#ifndef ROOT_TGraph2D
+#define ROOT_TGraph2D
+
+
+//////////////////////////////////////////////////////////////////////////
+//                                                                      //
+// TGraph2D                                                             //
+//                                                                      //
+// Graph 2D graphics class.                                             //
+//                                                                      //
+// This class uses the Delaunay triangles technique to interpolate and  //
+// render the data set.                                                 //
+//                                                                      //
+//////////////////////////////////////////////////////////////////////////
+
+#ifndef ROOT_TNamed 
+#include "TNamed.h"  
+#endif
+#ifndef ROOT_TH2
+#include "TH2.h"
+#endif
+
+class TGraph2D : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
+
+protected:
+
+   Int_t     fNp;          // Number of points to in the data set
+   Int_t     fNpx;         // number of bins along X in fHistogram
+   Int_t     fNpy;         // number of bins along Y in fHistogram
+   Int_t     fNdt;         //!Number of Delaunay triangles found
+   Int_t     fNxt;         //!Number of non-Delaunay triangles found
+   Int_t     fNhull;       //!Number of points in the hull
+   Double_t *fX;           //[fNp] Data set to be plotted. It is 
+   Double_t *fY;           //[fNp] stored in a normalized form.
+   Double_t *fZ;           //[fNp]
+   Double_t  fXmin;        //!Minimum value of fX
+   Double_t  fXmax;        //!Maximum value of fX
+   Double_t  fYmin;        //!Minimum value of fY
+   Double_t  fYmax;        //!Maximum value of fY
+   Double_t  fMargin;      // extra space (in %) around interpolated area for 2D histo
+   Double_t  fZout;        // Histogram bin height for points lying outside the convex hull
+   Double_t  fXoffset;     //!Offset fX
+   Double_t  fYoffset;     //!Offset fY
+   Double_t  fScaleFactor; //!Scale so the average of the fX and fY ranges is one
+   Double_t *fDist;        //!Array used to order mass points by distance
+   Int_t    *fTried;       //!Encoded triangles (see FileIt)
+   Int_t    *fHullPoints;  //!Hull points
+   Int_t    *fOrder;       //!Array used to order mass points by distance
+   TH2D *fHistogram;       //!2D histogram of z values linearly interpolated
+   
+           Double_t ComputeZ(Double_t x, Double_t y);
+	   void     CreateHistogram();
+           Bool_t   Enclose(Int_t T1, Int_t T2, Int_t T3, Int_t Ex) const;
+           void     FileIt(Int_t tri);
+           void     FillHistogram();
+           void     FindHull();
+           Bool_t   InHull(Int_t E, Int_t X) const;
+           Double_t Interpolate(Int_t TI1, Int_t TI2, Int_t TI3, Int_t E) const;
+           void     PaintMarkers();
+           void     PaintTriangles();
+           Int_t    TriEncode(Int_t T1, Int_t T2, Int_t T3) const;
+public:
+
+           TGraph2D();
+           TGraph2D(Int_t n, Double_t *x, Double_t *y, Double_t *z, Option_t *option="");
+           virtual ~TGraph2D();
+           Int_t    DistancetoPrimitive(Int_t px, Int_t py);
+           void     ExecuteEvent(Int_t event, Int_t px, Int_t py);
+           Double_t GetMargin() const {return fMargin;}
+           Int_t    GetNpx() const {return fNpx;}
+           Int_t    GetNpy() const {return fNpy;}
+           Double_t GetMarginBinsContent() const {return fZout;}
+           void     Paint(Option_t *option="");
+	   TH1     *Project(Option_t *option="x") const; // *MENU*
+           void     SetMargin(Double_t m=0.1); // *MENU*
+           void     SetNpx(Int_t npx=40); // *MENU*
+           void     SetNpy(Int_t npx=40); // *MENU*
+   virtual void     SetTitle(const char *title=""); // *MENU*
+           void     SetMarginBinsContent(Double_t z=0.); // *MENU*
+           void     Update();
+
+   ClassDef(TGraph2D,1)  //Set of n x[i],y[i],z[i] points with 3-d graphics including Delaunay triangulation
+};
+
+#endif