Graphics object made of three arrays X, Y and Z with the same number of points each.

Creating a TGraph2D

This class has different constructors:

With an array's dimension and three arrays x, y, and z:
auto g = new TGraph2D(n, x, y, z);

g
#define g(i)
Definition RSha256.hxx:105

TGraph2D::TGraph2D
TGraph2D()
Graph2D default constructor.
Definition TGraph2D.cxx:238

y
Double_t y[n]
Definition legend1.C:17

x
Double_t x[n]
Definition legend1.C:17

n
const Int_t n
Definition legend1.C:16

x, y, z arrays can be doubles, floats, or ints.
With an array's dimension only:
auto g = new TGraph2D(n);

The internal arrays are then filled with SetPoint(). The following line fills the internal arrays at the position i with the values x, y, z.
g->SetPoint(i, x, y, z);
Without parameters:
auto g = new TGraph2D();

again SetPoint() must be used to fill the internal arrays.
From a file:
auto g = new TGraph2D("graph.dat");

Arrays are read from the ASCII file "graph.dat" according to a specifies format. The default format is %lg %lg %lg

Note that in any of these three cases, SetPoint() can be used to change a data point or add a new one. If the data point index (i) is greater than the current size of the internal arrays, they are automatically extended.

Like TGraph some TGraph2D constructors do not have the TGraph2D title and name as parameters. For these constructors TGraph2D has the default title and name "Graph2D". To change the default title and name SetTitle and SetName should be called on the TGraph2D after its creation.

Drawing options

Specific drawing options can be used to paint a TGraph2D:

Option	Description
"TRI"	The Delaunay triangles are drawn using filled area. An hidden surface drawing technique is used. The surface is painted with the current fill area color. The edges of each triangles are painted with the current line color.
"TRIW"	The Delaunay triangles are drawn as wire frame.
"TRI1"	The Delaunay triangles are painted with color levels. The edges of each triangles are painted with the current line color.
"TRI2"	The Delaunay triangles are painted with color levels.
"P"	Draw a marker at each vertex.
"P0"	Draw a circle at each vertex. Each circle background is white.
"PCOL"	Draw a marker at each vertex. The color of each marker is defined according to its Z position.
"LINE"	Draw a 3D polyline.
"CONT5"	Draw a contour plot using Delaunay triangles.

A TGraph2D can be also drawn with any options valid to draw a 2D histogram (like COL, SURF, LEGO, CONT etc..).

When a TGraph2D is drawn with one of the 2D histogram drawing option, an intermediate 2D histogram is filled using the Delaunay triangles to interpolate the data set. The 2D histogram has equidistant bins along the X and Y directions. The number of bins along each direction can be change using SetNpx() and SetNpy(). Each bin is filled with the Z value found via a linear interpolation on the plane defined by the triangle above the (X,Y) coordinates of the bin center.

The existing (X,Y,Z) points can be randomly scattered. The Delaunay triangles are build in the (X,Y) plane. These 2D triangles are then used to define flat planes in (X,Y,Z) over which the interpolation is done to fill the 2D histogram. The 3D triangles int takes build a 3D surface in the form of tessellating triangles at various angles. The triangles found can be drawn in 3D with one of the TGraph2D specific drawing options.

The histogram generated by the Delaunay interpolation can be accessed using the GetHistogram() method.

The axis settings (title, ranges etc ...) can be changed accessing the axis via the GetXaxis GetYaxis and GetZaxis methods. They access the histogram axis created at drawing time only. Therefore they should called after the TGraph2D is drawn:

auto g = new TGraph2D();
 
[...]
 
g->Draw("tri1");
gPad->Update();
g->GetXaxis()->SetTitle("X axis title");

Examples

SURF1 Example

{
   auto c = new TCanvas("c","Graph2D example",0,0,600,400);
   Double_t x, y, z, P = 6.;
   Int_t np = 200;
   auto dt = new TGraph2D();
   dt->SetTitle("Graph title; X axis title; Y axis title; Z axis title");
   auto r = new TRandom();
   for (Int_t N=0; N<np; N++) {
      x = 2*P*(r->Rndm(N))-P;
      y = 2*P*(r->Rndm(N))-P;
      z = (sin(x)/x)*(sin(y)/y)+0.2;
      dt->SetPoint(N,x,y,z);
   }
   gStyle->SetPalette(1);
   dt->Draw("surf1");
}

Fitting Example

2D graphs can be fitted as shown by the following example:

 
#include <TMath.h>
#include <TGraph2D.h>
#include <TRandom.h>
#include <TStyle.h>
#include <TCanvas.h>
#include <TF2.h>
#include <TH1.h>
 
void graph2dfit()
{
   gStyle->SetOptStat(0);
   gStyle->SetOptFit();
 
   auto c = new TCanvas("c","Graph2D example",0,0,600,800);
   c->Divide(2,3);
 
   double rnd, x, y, z;
   double e = 0.3;
   int nd = 400;
   int np = 10000;
 
   TRandom r;
   double fl = 6;
   auto f2 = new TF2("f2","1000*(([0]*sin(x)/x)*([1]*sin(y)/y))+200",
      -fl,fl,-fl,fl);
   f2->SetParameters(1,1);
   auto dt = new TGraph2D();
 
   // Fill the 2D graph
   double zmax = 0;
   for (int N=0; N<nd; N++) {
      f2->GetRandom2(x,y);
      // Generate a random number in [-e,e]
      rnd = 2*r.Rndm()*e-e;
      z = f2->Eval(x,y)*(1+rnd);
      if (z>zmax) zmax = z;
      dt->SetPoint(N,x,y,z);
   }
 
   double hr = 350;
   auto h1 = new TH1D("h1",
   "#splitline{Difference between Original}{#splitline{function and Function}{with noise}}",
   100, -hr, hr);
   auto h2 = new TH1D("h2",
   "#splitline{Difference between Original}{#splitline{function and Delaunay triangles}{interpolation}}",
   100, -hr, hr);
   auto h3 = new TH1D("h3",
   "#splitline{Difference between Original}{function and Minuit fit}",
   500, -hr, hr);
 
   f2->SetParameters(0.5,1.5);
   dt->Fit(f2);
   auto fit2 = (TF2*)dt->FindObject("f2");
 
   f2->SetParameters(1,1);
 
   for (int N=0; N<np; N++) {
      f2->GetRandom2(x,y);
      // Generate a random number in [-e,e]
      rnd = 2*r.Rndm()*e-e;
      z = f2->Eval(x,y)*(1+rnd);
      h1->Fill(f2->Eval(x,y)-z);
      z = dt->Interpolate(x,y);
      h2->Fill(f2->Eval(x,y)-z);
      z = fit2->Eval(x,y);
      h3->Fill(f2->Eval(x,y)-z);
   }
 
   c->cd(1);
   f2->SetTitle("Original function with Graph2D points on top");
   f2->SetMaximum(zmax);
   gStyle->SetHistTopMargin(0);
   f2->Draw("surf1");
   dt->Draw("same p0");
 
   c->cd(3);
   dt->SetMargin(0.1);
   dt->SetFillColor(36);
   dt->SetTitle("Histogram produced with Delaunay interpolation");
   dt->Draw("surf4");
 
   c->cd(5);
   fit2->SetTitle("Minuit fit result on the Graph2D points");
   fit2->Draw("surf1");
 
   h1->SetFillColor(47);
   h2->SetFillColor(38);
   h3->SetFillColor(29);
 
   c->cd(2); h1->Fit("gaus","Q") ; h1->Draw();
   c->cd(4); h2->Fit("gaus","Q") ; h2->Draw();
   c->cd(6); h3->Fit("gaus","Q") ; h3->Draw();
   c->cd();
}

PCOL Example

Example showing the PCOL option.

{
   auto c = new TCanvas("c","Graph2D example",0,0,600,400);
   Double_t P = 5.;
   Int_t npx  = 20 ;
   Int_t npy  = 20 ;
   Double_t x = -P;
   Double_t y = -P;
   Double_t z;
   Int_t k = 0;
   Double_t dx = (2*P)/npx;
   Double_t dy = (2*P)/npy;
   auto dt = new TGraph2D(npx*npy);
   dt->SetNpy(41);
   dt->SetNpx(40);
   for (Int_t i=0; i<npx; i++) {
      for (Int_t j=0; j<npy; j++) {
         z = sin(sqrt(x*x+y*y))+1;
         dt->SetPoint(k,x,y,z);
         k++;
         y = y+dy;
      }
      x = x+dx;
      y = -P;
   }
   gStyle->SetPalette(1);
   dt->SetMarkerStyle(20);
   dt->Draw("pcol");
}

Definition of the Delaunay triangulation (After B. Delaunay)

For a set S of points in the Euclidean plane, the unique triangulation DT(S) of S such that no point in S is inside the circumcircle of any triangle in DT(S). DT(S) is the dual of the Voronoi diagram of S. If n is the number of points in S, the Voronoi diagram of S is the partitioning of the plane containing S points into n convex polygons such that each polygon contains exactly one point and every point in a given polygon is closer to its central point than to any other. A Voronoi diagram is sometimes also known as a Dirichlet tessellation.

This applet gives a nice practical view of Delaunay triangulation and Voronoi diagram.

Definition at line 41 of file TGraph2D.h.

Public Member Functions
	TGraph2D ()
	Graph2D default constructor.

	TGraph2D (const char filename, const char format="%lg %lg %lg", Option_t *option="")
	Graph2D constructor reading input from filename filename is assumed to contain at least three columns of numbers.

	TGraph2D (const char name, const char title, Int_t n, Double_t x, Double_t y, Double_t *z)
	Graph2D constructor with name, title and three vectors of doubles as input.

	TGraph2D (const TGraph2D &)
	Graph2D copy constructor.

	TGraph2D (Int_t n)
	Graph2D constructor.

	TGraph2D (Int_t n, Double_t x, Double_t y, Double_t *z)
	Graph2D constructor with three vectors of doubles as input.

	TGraph2D (Int_t n, Float_t x, Float_t y, Float_t *z)
	Graph2D constructor with three vectors of floats as input.

	TGraph2D (Int_t n, Int_t x, Int_t y, Int_t *z)
	Graph2D constructor with three vectors of ints as input.

	TGraph2D (TH2 *h2)
	Graph2D constructor with a TH2 (h2) as input.

	~TGraph2D () override
	TGraph2D destructor.

virtual void	AddPoint (Double_t x, Double_t y, Double_t z)
	Append a new point to the graph.

void	Browse (TBrowser *) override
	Browse.

void	Clear (Option_t *option="") override
	Free all memory allocated by this object.

virtual void	DirectoryAutoAdd (TDirectory *)
	Perform the automatic addition of the graph to the given directory.

Int_t	DistancetoPrimitive (Int_t px, Int_t py) override
	Computes distance from point px,py to a graph.

void	Draw (Option_t *option="P0") override
	Specific drawing options can be used to paint a TGraph2D:

void	ExecuteEvent (Int_t event, Int_t px, Int_t py) override
	Executes action corresponding to one event.

TObject *	FindObject (const char *name) const override
	search object named name in the list of functions

TObject *	FindObject (const TObject *obj) const override
	search object obj in the list of functions

virtual TFitResultPtr	Fit (const char formula, Option_t option="", Option_t *goption="")
	Fits this graph with function with name fname Predefined functions such as gaus, expo and poln are automatically created by ROOT.

virtual TFitResultPtr	Fit (TF2 f2, Option_t option="", Option_t *goption="")
	Fits this 2D graph with function f2.

virtual void	FitPanel ()
	Display a GUI panel with all graph fit options.

TList *	GetContourList (Double_t contour)
	Returns the X and Y graphs building a contour.

TDirectory *	GetDirectory () const

virtual Double_t	GetErrorX (Int_t bin) const
	This function is called by Graph2DFitChisquare.

virtual Double_t	GetErrorY (Int_t bin) const
	This function is called by Graph2DFitChisquare.

virtual Double_t	GetErrorZ (Int_t bin) const
	This function is called by Graph2DFitChisquare.

virtual Double_t *	GetEX () const

virtual Double_t *	GetEXhigh () const

virtual Double_t *	GetEXlow () const

virtual Double_t *	GetEY () const

virtual Double_t *	GetEYhigh () const

virtual Double_t *	GetEYlow () const

virtual Double_t *	GetEZ () const

virtual Double_t *	GetEZhigh () const

virtual Double_t *	GetEZlow () const

TH2D *	GetHistogram (Option_t *option="")
	By default returns a pointer to the Delaunay histogram.

TList *	GetListOfFunctions () const

Double_t	GetMargin () const

Double_t	GetMaximum () const

Double_t	GetMinimum () const

Int_t	GetN () const

Int_t	GetNpx () const

Int_t	GetNpy () const

virtual Int_t	GetPoint (Int_t i, Double_t &x, Double_t &y, Double_t &z) const
	Get x, y and z values for point number i.

Double_t *	GetX () const

TAxis *	GetXaxis () const
	Get x axis of the graph.

Double_t	GetXmax () const
	Returns the X maximum.

virtual Double_t	GetXmaxE () const

Double_t	GetXmin () const
	Returns the X minimum.

virtual Double_t	GetXminE () const

Double_t *	GetY () const

TAxis *	GetYaxis () const
	Get y axis of the graph.

Double_t	GetYmax () const
	Returns the Y maximum.

virtual Double_t	GetYmaxE () const

Double_t	GetYmin () const
	Returns the Y minimum.

virtual Double_t	GetYminE () const

Double_t *	GetZ () const

TAxis *	GetZaxis () const
	Get z axis of the graph.

Double_t	GetZmax () const
	Returns the Z maximum.

virtual Double_t	GetZmaxE () const

Double_t	GetZmin () const
	Returns the Z minimum.

virtual Double_t	GetZminE () const

Double_t	Interpolate (Double_t x, Double_t y)
	Finds the z value at the position (x,y) thanks to the Delaunay interpolation.

TClass *	IsA () const override

TGraph2D &	operator= (const TGraph2D &)
	Graph2D operator "=".

void	Paint (Option_t *option="") override
	Paints this 2D graph with its current attributes.

void	Print (Option_t *chopt="") const override
	Print 2D graph values.

TH1 *	Project (Option_t *option="x") const
	Projects a 2-d graph into 1 or 2-d histograms depending on the option parameter.

Int_t	RemovePoint (Int_t ipoint)
	Deletes point number ipoint.

void	SavePrimitive (std::ostream &out, Option_t *option="") override
	Saves primitive as a C++ statement(s) on output stream out.

virtual void	Scale (Double_t c1=1., Option_t *option="z")
	Multiply the values of a TGraph2D by a constant c1.

virtual void	Set (Int_t n)
	Set number of points in the 2D graph.

virtual void	SetDirectory (TDirectory *dir)
	By default when an 2D graph is created, it is added to the list of 2D graph objects in the current directory in memory.

virtual void	SetHistogram (TH2 h, Option_t option="")
	Sets the histogram to be filled.

void	SetMargin (Double_t m=0.1)
	Sets the extra space (in %) around interpolated area for the 2D histogram.

void	SetMarginBinsContent (Double_t z=0.)
	Sets the histogram bin height for points lying outside the TGraphDelaunay convex hull ie: the bins in the margin.

void	SetMaximum (Double_t maximum=-1111)
	Set maximum.

void	SetMaxIter (Int_t n=100000)

void	SetMinimum (Double_t minimum=-1111)
	Set minimum.

void	SetName (const char *name) override
	Changes the name of this 2D graph.

void	SetNameTitle (const char name, const char title) override
	Change the name and title of this 2D graph.

void	SetNpx (Int_t npx=40)
	Sets the number of bins along X used to draw the function.

void	SetNpy (Int_t npx=40)
	Sets the number of bins along Y used to draw the function.

virtual void	SetPoint (Int_t point, Double_t x, Double_t y, Double_t z)
	Sets point number n.

void	SetTitle (const char *title="") override
	Sets the 2D graph title.

void	Streamer (TBuffer &) override
	Stream a class object.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

	TNamed (const TString &name, const TString &title)

virtual	~TNamed ()
	TNamed destructor.

void	Clear (Option_t *option="") override
	Set name and title to empty strings ("").

TObject *	Clone (const char *newname="") const override
	Make a clone of an object using the Streamer facility.

Int_t	Compare (const TObject *obj) const override
	Compare two TNamed objects.

void	Copy (TObject &named) const override
	Copy this to obj.

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer.

const char *	GetName () const override
	Returns name of object.

const char *	GetTitle () const override
	Returns title of object.

ULong_t	Hash () const override
	Return hash value for this object.

TClass *	IsA () const override

Bool_t	IsSortable () const override

void	ls (Option_t *option="") const override
	List TNamed name and title.

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator.

void	Print (Option_t *option="") const override
	Print TNamed name and title.

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject.

void	Streamer (TBuffer &) override
	Stream an object of class TObject.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor.

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract.

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad.

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object.

virtual const char *	ClassName () const
	Returns name of class to which the object belongs.

virtual void	Delete (Option_t *option="")
	Delete this object.

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs.

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad with: `gROOT->SetSelectedPad(c1)`.

virtual void	Dump () const
	Dump contents of object on stdout.

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message.

virtual void	Execute (const char method, const char params, Int_t *error=nullptr)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=nullptr)
	Execute method on this object with parameters stored in the TObjArray.

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message.

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object.

virtual const char *	GetIconName () const
	Returns mime type name of object.

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py).

virtual Option_t *	GetOption () const

virtual UInt_t	GetUniqueID () const
	Return the unique object id.

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out.

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e.

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message.

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname".

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl.

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas.

void	InvertBit (UInt_t f)

Bool_t	IsDestructed () const
	IsDestructed.

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory).

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects).

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary).

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification (the base implementation is no-op).

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete.

void	operator delete (void *ptr)
	Operator delete.

void	operator delete (void ptr, void vp)
	Only called by placement new when throwing an exception.

void	operator delete[] (void *ptr)
	Operator delete [].

void	operator delete[] (void ptr, void vp)
	Only called by placement new[] when throwing an exception.

void *	operator new (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz)

void *	operator new[] (size_t sz, void *vp)

TObject &	operator= (const TObject &rhs)
	TObject assignment operator.

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list.

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory.

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list.

void	ResetBit (UInt_t f)

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename.

void	SetBit (UInt_t f)

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f.

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object.

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message.

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked.

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message.

virtual Int_t	Write (const char *name=nullptr, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

virtual Int_t	Write (const char *name=nullptr, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory.

Public Member Functions inherited from TAttLine
	TAttLine ()
	AttLine default constructor.

	TAttLine (Color_t lcolor, Style_t lstyle, Width_t lwidth)
	AttLine normal constructor.

virtual	~TAttLine ()
	AttLine destructor.

void	Copy (TAttLine &attline) const
	Copy this line attributes to a new TAttLine.

Int_t	DistancetoLine (Int_t px, Int_t py, Double_t xp1, Double_t yp1, Double_t xp2, Double_t yp2)
	Compute distance from point px,py to a line.

virtual Color_t	GetLineColor () const
	Return the line color.

virtual Style_t	GetLineStyle () const
	Return the line style.

virtual Width_t	GetLineWidth () const
	Return the line width.

virtual void	Modify ()
	Change current line attributes if necessary.

virtual void	ResetAttLine (Option_t *option="")
	Reset this line attributes to default values.

virtual void	SaveLineAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t widdef=1)
	Save line attributes as C++ statement(s) on output stream out.

virtual void	SetLineAttributes ()
	Invoke the DialogCanvas Line attributes.

virtual void	SetLineColor (Color_t lcolor)
	Set the line color.

virtual void	SetLineColorAlpha (Color_t lcolor, Float_t lalpha)
	Set a transparent line color.

virtual void	SetLineStyle (Style_t lstyle)
	Set the line style.

virtual void	SetLineWidth (Width_t lwidth)
	Set the line width.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TAttFill
	TAttFill ()
	AttFill default constructor.

	TAttFill (Color_t fcolor, Style_t fstyle)
	AttFill normal constructor.

virtual	~TAttFill ()
	AttFill destructor.

void	Copy (TAttFill &attfill) const
	Copy this fill attributes to a new TAttFill.

virtual Color_t	GetFillColor () const
	Return the fill area color.

virtual Style_t	GetFillStyle () const
	Return the fill area style.

virtual Bool_t	IsTransparent () const

virtual void	Modify ()
	Change current fill area attributes if necessary.

virtual void	ResetAttFill (Option_t *option="")
	Reset this fill attributes to default values.

virtual void	SaveFillAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1001)
	Save fill attributes as C++ statement(s) on output stream out.

virtual void	SetFillAttributes ()
	Invoke the DialogCanvas Fill attributes.

virtual void	SetFillColor (Color_t fcolor)
	Set the fill area color.

virtual void	SetFillColorAlpha (Color_t fcolor, Float_t falpha)
	Set a transparent fill color.

virtual void	SetFillStyle (Style_t fstyle)
	Set the fill area style.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TAttMarker
	TAttMarker ()
	TAttMarker default constructor.

	TAttMarker (Color_t color, Style_t style, Size_t msize)
	TAttMarker normal constructor.

virtual	~TAttMarker ()
	TAttMarker destructor.

void	Copy (TAttMarker &attmarker) const
	Copy this marker attributes to a new TAttMarker.

virtual Color_t	GetMarkerColor () const
	Return the marker color.

virtual Size_t	GetMarkerSize () const
	Return the marker size.

virtual Style_t	GetMarkerStyle () const
	Return the marker style.

virtual void	Modify ()
	Change current marker attributes if necessary.

virtual void	ResetAttMarker (Option_t *toption="")
	Reset this marker attributes to the default values.

virtual void	SaveMarkerAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t sizdef=1)
	Save line attributes as C++ statement(s) on output stream out.

virtual void	SetMarkerAttributes ()
	Invoke the DialogCanvas Marker attributes.

virtual void	SetMarkerColor (Color_t mcolor=1)
	Set the marker color.

virtual void	SetMarkerColorAlpha (Color_t mcolor, Float_t malpha)
	Set a transparent marker color.

virtual void	SetMarkerSize (Size_t msize=1)
	Set the marker size.

virtual void	SetMarkerStyle (Style_t mstyle=1)
	Set the marker style.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Static Public Member Functions
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TNamed
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TObject
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Longptr_t	GetDtorOnly ()
	Return destructor only flag.

static Bool_t	GetObjectStat ()
	Get status of object stat flag.

static void	SetDtorOnly (void *obj)
	Set destructor only flag.

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable.

Static Public Member Functions inherited from TAttLine
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TAttFill
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TAttMarker
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Width_t	GetMarkerLineWidth (Style_t style)
	Internal helper function that returns the line width of the given marker style (0 = filled marker)

static Style_t	GetMarkerStyleBase (Style_t style)
	Internal helper function that returns the corresponding marker style with line width 1 for the given style.

Protected Member Functions
void	Build (Int_t n)
	Creates the 2D graph basic data structure.

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected).

void	MakeZombie ()

Protected Attributes
TObject *	fDelaunay
	! Pointer to Delaunay interpolator object

TDirectory *	fDirectory
	!Pointer to directory holding this 2D graph

TList *	fFunctions
	Pointer to list of functions (fits and user)

TH2D *	fHistogram
	!2D histogram of z values linearly interpolated on the triangles

Double_t	fMargin
	Extra space (in %) around interpolated area for fHistogram.

Double_t	fMaximum
	Maximum value for plotting along z.

Int_t	fMaxIter
	Maximum number of iterations to find Delaunay triangles.

Double_t	fMinimum
	Minimum value for plotting along z.

Int_t	fNpoints
	Number of points in the data set.

Int_t	fNpx
	Number of bins along X in fHistogram.

Int_t	fNpy
	Number of bins along Y in fHistogram.

TVirtualHistPainter *	fPainter
	!Pointer to histogram painter

Int_t	fSize
	!Real size of fX, fY and fZ

Double_t *	fX
	[fNpoints]

Double_t *	fY
	[fNpoints] Data set to be plotted

Double_t *	fZ
	[fNpoints]

Double_t	fZout
	fHistogram bin height for points lying outside the interpolated area

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Protected Attributes inherited from TAttLine
Color_t	fLineColor
	Line color.

Style_t	fLineStyle
	Line style.

Width_t	fLineWidth
	Line width.

Protected Attributes inherited from TAttFill
Color_t	fFillColor
	Fill area color.

Style_t	fFillStyle
	Fill area style.

Protected Attributes inherited from TAttMarker
Color_t	fMarkerColor
	Marker color.

Size_t	fMarkerSize
	Marker size.

Style_t	fMarkerStyle
	Marker style.

Private Types
enum	EStatusBits { kOldInterpolation = (1ULL << ( 15 )) }

Private Member Functions
void	CreateInterpolator (Bool_t oldInterp)
	Add a TGraphDelaunay in the list of the fHistogram's functions.

Private Attributes
Bool_t	fUserHisto

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

enum	{ kSingleKey = (1ULL << ( 0 )) , kOverwrite = (1ULL << ( 1 )) , kWriteDelete = (1ULL << ( 2 )) }

enum	EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }

enum	EStatusBits { kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) , kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 )) }

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = (1ULL << ( 3 )) }

#include <TGraph2D.h>

Inheritance diagram for TGraph2D:

[legend]

Member Enumeration Documentation

◆ EStatusBits

enum TGraph2D::EStatusBits

private

Enumerator
kOldInterpolation

Definition at line 69 of file TGraph2D.h.

Constructor & Destructor Documentation

◆ TGraph2D() [1/9]

TGraph2D::TGraph2D ( )

Graph2D default constructor.

Definition at line 238 of file TGraph2D.cxx.

◆ TGraph2D() [2/9]

TGraph2D::TGraph2D ( Int_t n )

Graph2D constructor.

The arrays fX, fY and fZ should be filled via calls to SetPoint

Definition at line 388 of file TGraph2D.cxx.

◆ TGraph2D() [3/9]

TGraph2D::TGraph2D	(	Int_t	n,
		Int_t *	x,
		Int_t *	y,
		Int_t *	z
	)

Graph2D constructor with three vectors of ints as input.

Definition at line 265 of file TGraph2D.cxx.

◆ TGraph2D() [4/9]

TGraph2D::TGraph2D	(	Int_t	n,
		Float_t *	x,
		Float_t *	y,
		Float_t *	z
	)

Graph2D constructor with three vectors of floats as input.

Definition at line 283 of file TGraph2D.cxx.

◆ TGraph2D() [5/9]

TGraph2D::TGraph2D	(	Int_t	n,
		Double_t *	x,
		Double_t *	y,
		Double_t *	z
	)

Graph2D constructor with three vectors of doubles as input.

Definition at line 301 of file TGraph2D.cxx.

◆ TGraph2D() [6/9]

TGraph2D::TGraph2D ( TH2 * h2 )

Graph2D constructor with a TH2 (h2) as input.

Only the h2's bins within the X and Y axis ranges are used. Empty bins, recognized when both content and errors are zero, are excluded.

Definition at line 321 of file TGraph2D.cxx.

◆ TGraph2D() [7/9]

TGraph2D::TGraph2D	(	const char *	name,
		const char *	title,
		Int_t	n,
		Double_t *	x,
		Double_t *	y,
		Double_t *	z
	)

Graph2D constructor with name, title and three vectors of doubles as input.

name : name of 2D graph (avoid blanks) title : 2D graph title if title is of the form "stringt;stringx;stringy;stringz" the 2D graph title is set to stringt, the x axis title to stringx, the y axis title to stringy,etc

Definition at line 368 of file TGraph2D.cxx.

◆ TGraph2D() [8/9]

TGraph2D::TGraph2D	(	const char *	filename,
		const char *	format = `"%lg %lg %lg"`,
		Option_t *	option = `""`
	)

Graph2D constructor reading input from filename filename is assumed to contain at least three columns of numbers.

For files separated by a specific delimiter different from ' ' and '\t' (e.g. ';' in csv files) you can avoid using %*s to bypass this delimiter by explicitly specify the "option" argument, e.g. option=" \\t,;" for columns of figures separated by any of these characters (' ', '\t', ',', ';') used once (e.g. "1;1") or in a combined way (" 1;,;; 1"). Note in that case, the instantiation is about 2 times slower.

Definition at line 410 of file TGraph2D.cxx.

◆ TGraph2D() [9/9]

TGraph2D::TGraph2D ( const TGraph2D & g )

Graph2D copy constructor.

copy everything apart from the list of contained functions

Definition at line 530 of file TGraph2D.cxx.

◆ ~TGraph2D()

TGraph2D::~TGraph2D ( )

override

TGraph2D destructor.

Definition at line 556 of file TGraph2D.cxx.

Member Function Documentation

◆ AddPoint()

virtual void TGraph2D::AddPoint	(	Double_t	x,
		Double_t	y,
		Double_t	z
	)

inlinevirtual

Append a new point to the graph.

Definition at line 93 of file TGraph2D.h.

◆ Browse()

void TGraph2D::Browse ( TBrowser * )

overridevirtual

Browse.

Reimplemented from TObject.

Definition at line 647 of file TGraph2D.cxx.

◆ Build()

void TGraph2D::Build ( Int_t n )

protected

Creates the 2D graph basic data structure.

Definition at line 610 of file TGraph2D.cxx.

◆ Class()

static TClass * TGraph2D::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TGraph2D::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TGraph2D::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 169 of file TGraph2D.h.

◆ Clear()

void TGraph2D::Clear ( Option_t * option = "" )

overridevirtual

Free all memory allocated by this object.

Reimplemented from TObject.

Definition at line 657 of file TGraph2D.cxx.

◆ CreateInterpolator()

void TGraph2D::CreateInterpolator ( Bool_t oldInterp )

private

Add a TGraphDelaunay in the list of the fHistogram's functions.

Definition at line 944 of file TGraph2D.cxx.

◆ DeclFileName()

static const char * TGraph2D::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 169 of file TGraph2D.h.

◆ DirectoryAutoAdd()

void TGraph2D::DirectoryAutoAdd ( TDirectory * dir )

virtual

Perform the automatic addition of the graph to the given directory.

Note this function is called in place when the semantic requires this object to be added to a directory (I.e. when being read from a TKey or being Cloned)

Definition at line 691 of file TGraph2D.cxx.

◆ DistancetoPrimitive()

Int_t TGraph2D::DistancetoPrimitive	(	Int_t	px,
		Int_t	py
	)

overridevirtual

Computes distance from point px,py to a graph.

Reimplemented from TObject.

Definition at line 706 of file TGraph2D.cxx.

◆ Draw()

void TGraph2D::Draw ( Option_t * option = "P0" )

overridevirtual

Specific drawing options can be used to paint a TGraph2D:

"TRI" : The Delaunay triangles are drawn using filled area. An hidden surface drawing technique is used. The surface is painted with the current fill area color. The edges of each triangles are painted with the current line color.
"TRIW" : The Delaunay triangles are drawn as wire frame
"TRI1" : The Delaunay triangles are painted with color levels. The edges of each triangles are painted with the current line color.
"TRI2" : the Delaunay triangles are painted with color levels.
"P" : Draw a marker at each vertex
"P0" : Draw a circle at each vertex. Each circle background is white.
"PCOL" : Draw a marker at each vertex. The color of each marker is defined according to its Z position.
"CONT" : Draw contours
"LINE" : Draw a 3D polyline

A TGraph2D can be also drawn with ANY options valid to draw a 2D histogram.

When a TGraph2D is drawn with one of the 2D histogram drawing option, a intermediate 2D histogram is filled using the Delaunay triangles technique to interpolate the data set.

Reimplemented from TObject.

Definition at line 738 of file TGraph2D.cxx.

◆ ExecuteEvent()

void TGraph2D::ExecuteEvent	(	Int_t	event,
		Int_t	px,
		Int_t	py
	)

overridevirtual

Executes action corresponding to one event.

Reimplemented from TObject.

Definition at line 758 of file TGraph2D.cxx.

◆ FindObject() [1/2]

TObject * TGraph2D::FindObject ( const char * name ) const

overridevirtual

search object named name in the list of functions

Reimplemented from TObject.

Definition at line 767 of file TGraph2D.cxx.

◆ FindObject() [2/2]

TObject * TGraph2D::FindObject ( const TObject * obj ) const

overridevirtual

search object obj in the list of functions

Reimplemented from TObject.

Definition at line 777 of file TGraph2D.cxx.

◆ Fit() [1/2]

TFitResultPtr TGraph2D::Fit	(	const char *	fname,
		Option_t *	option = `""`,
		Option_t *	goption = `""`
	)

virtual

Fits this graph with function with name fname Predefined functions such as gaus, expo and poln are automatically created by ROOT.

fname can also be a formula, accepted by the linear fitter (linear parts divided by "++" sign), for example "x++sin(y)" for fitting "[0]*x+[1]*sin(y)"

Definition at line 791 of file TGraph2D.cxx.

◆ Fit() [2/2]

TFitResultPtr TGraph2D::Fit	(	TF2 *	f2,
		Option_t *	option = `""`,
		Option_t *	goption = `""`
	)

virtual

Fits this 2D graph with function f2.

f2 is an already predefined function created by TF2.

See TGraph::Fit for the available fitting options and fitting notes

Definition at line 818 of file TGraph2D.cxx.

◆ FitPanel()

void TGraph2D::FitPanel ( )

virtual

Display a GUI panel with all graph fit options.

See class TFitEditor for example

Definition at line 837 of file TGraph2D.cxx.

◆ GetContourList()

TList * TGraph2D::GetContourList ( Double_t contour )

Returns the X and Y graphs building a contour.

A contour level may consist in several parts not connected to each other. This function returns them in a graphs' list.

Definition at line 896 of file TGraph2D.cxx.

◆ GetDirectory()

TDirectory * TGraph2D::GetDirectory ( ) const

inline

Definition at line 106 of file TGraph2D.h.

◆ GetErrorX()

Double_t TGraph2D::GetErrorX ( Int_t bin ) const

virtual

This function is called by Graph2DFitChisquare.

It always returns a negative value. Real implementation in TGraph2DErrors

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 915 of file TGraph2D.cxx.

◆ GetErrorY()

Double_t TGraph2D::GetErrorY ( Int_t bin ) const

virtual

This function is called by Graph2DFitChisquare.

It always returns a negative value. Real implementation in TGraph2DErrors

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 925 of file TGraph2D.cxx.

◆ GetErrorZ()

Double_t TGraph2D::GetErrorZ ( Int_t bin ) const

virtual

This function is called by Graph2DFitChisquare.

It always returns a negative value. Real implementation in TGraph2DErrors

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 935 of file TGraph2D.cxx.

◆ GetEX()

virtual Double_t * TGraph2D::GetEX ( ) const

inlinevirtual

Reimplemented in TGraph2DErrors.

Definition at line 124 of file TGraph2D.h.

◆ GetEXhigh()

virtual Double_t * TGraph2D::GetEXhigh ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 128 of file TGraph2D.h.

◆ GetEXlow()

virtual Double_t * TGraph2D::GetEXlow ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 127 of file TGraph2D.h.

◆ GetEY()

virtual Double_t * TGraph2D::GetEY ( ) const

inlinevirtual

Reimplemented in TGraph2DErrors.

Definition at line 125 of file TGraph2D.h.

◆ GetEYhigh()

virtual Double_t * TGraph2D::GetEYhigh ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 130 of file TGraph2D.h.

◆ GetEYlow()

virtual Double_t * TGraph2D::GetEYlow ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 129 of file TGraph2D.h.

◆ GetEZ()

virtual Double_t * TGraph2D::GetEZ ( ) const

inlinevirtual

Reimplemented in TGraph2DErrors.

Definition at line 126 of file TGraph2D.h.

◆ GetEZhigh()

virtual Double_t * TGraph2D::GetEZhigh ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 132 of file TGraph2D.h.

◆ GetEZlow()

virtual Double_t * TGraph2D::GetEZlow ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors.

Definition at line 131 of file TGraph2D.h.

◆ GetHistogram()

TH2D * TGraph2D::GetHistogram ( Option_t * option = "" )

By default returns a pointer to the Delaunay histogram.

If fHistogram doesn't exist, books the 2D histogram fHistogram with a margin around the hull. Calls TGraphDelaunay::Interpolate at each bin centre to build up an interpolated 2D histogram.

If the "empty" option is selected, returns an empty histogram booked with the limits of fX, fY and fZ. This option is used when the data set is drawn with markers only. In that particular case there is no need to find the Delaunay triangles.

By default use the new interpolation routine based on Triangles If the option "old" the old interpolation is used

Definition at line 979 of file TGraph2D.cxx.

◆ GetListOfFunctions()

TList * TGraph2D::GetListOfFunctions ( ) const

inline

Definition at line 110 of file TGraph2D.h.

◆ GetMargin()

Double_t TGraph2D::GetMargin ( ) const

inline

Definition at line 114 of file TGraph2D.h.

◆ GetMaximum()

Double_t TGraph2D::GetMaximum ( ) const

inline

Definition at line 115 of file TGraph2D.h.

◆ GetMinimum()

Double_t TGraph2D::GetMinimum ( ) const

inline

Definition at line 116 of file TGraph2D.h.

◆ GetN()

Int_t TGraph2D::GetN ( ) const

inline

Definition at line 120 of file TGraph2D.h.

◆ GetNpx()

Int_t TGraph2D::GetNpx ( ) const

inline

Definition at line 107 of file TGraph2D.h.

◆ GetNpy()

Int_t TGraph2D::GetNpy ( ) const

inline

Definition at line 108 of file TGraph2D.h.

◆ GetPoint()

Int_t TGraph2D::GetPoint	(	Int_t	i,
		Double_t &	x,
		Double_t &	y,
		Double_t &	z
	)		const

virtual

Get x, y and z values for point number i.

The function returns -1 in case of an invalid request or the point number otherwise

Definition at line 1195 of file TGraph2D.cxx.

◆ GetX()

Double_t * TGraph2D::GetX ( ) const

inline

Definition at line 121 of file TGraph2D.h.

◆ GetXaxis()

TAxis * TGraph2D::GetXaxis ( ) const

Get x axis of the graph.

Definition at line 861 of file TGraph2D.cxx.

◆ GetXmax()

Double_t TGraph2D::GetXmax ( ) const

Returns the X maximum.

Definition at line 1129 of file TGraph2D.cxx.

◆ GetXmaxE()

virtual Double_t TGraph2D::GetXmaxE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 139 of file TGraph2D.h.

◆ GetXmin()

Double_t TGraph2D::GetXmin ( ) const

Returns the X minimum.

Definition at line 1140 of file TGraph2D.cxx.

◆ GetXminE()

virtual Double_t TGraph2D::GetXminE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 140 of file TGraph2D.h.

◆ GetY()

Double_t * TGraph2D::GetY ( ) const

inline

Definition at line 122 of file TGraph2D.h.

◆ GetYaxis()

TAxis * TGraph2D::GetYaxis ( ) const

Get y axis of the graph.

Definition at line 872 of file TGraph2D.cxx.

◆ GetYmax()

Double_t TGraph2D::GetYmax ( ) const

Returns the Y maximum.

Definition at line 1151 of file TGraph2D.cxx.

◆ GetYmaxE()

virtual Double_t TGraph2D::GetYmaxE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 141 of file TGraph2D.h.

◆ GetYmin()

Double_t TGraph2D::GetYmin ( ) const

Returns the Y minimum.

Definition at line 1162 of file TGraph2D.cxx.

◆ GetYminE()

virtual Double_t TGraph2D::GetYminE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 142 of file TGraph2D.h.

◆ GetZ()

Double_t * TGraph2D::GetZ ( ) const

inline

Definition at line 123 of file TGraph2D.h.

◆ GetZaxis()

TAxis * TGraph2D::GetZaxis ( ) const

Get z axis of the graph.

Definition at line 883 of file TGraph2D.cxx.

◆ GetZmax()

Double_t TGraph2D::GetZmax ( ) const

Returns the Z maximum.

Definition at line 1173 of file TGraph2D.cxx.

◆ GetZmaxE()

virtual Double_t TGraph2D::GetZmaxE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 143 of file TGraph2D.h.

◆ GetZmin()

Double_t TGraph2D::GetZmin ( ) const

Returns the Z minimum.

Definition at line 1184 of file TGraph2D.cxx.

◆ GetZminE()

virtual Double_t TGraph2D::GetZminE ( ) const

inlinevirtual

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 144 of file TGraph2D.h.

◆ Interpolate()

Double_t TGraph2D::Interpolate	(	Double_t	x,
		Double_t	y
	)

Finds the z value at the position (x,y) thanks to the Delaunay interpolation.

Definition at line 1209 of file TGraph2D.cxx.

◆ IsA()

TClass * TGraph2D::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TObject.

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 169 of file TGraph2D.h.

◆ operator=()

TGraph2D & TGraph2D::operator= ( const TGraph2D & g )

Graph2D operator "=".

Definition at line 565 of file TGraph2D.cxx.

◆ Paint()

void TGraph2D::Paint ( Option_t * option = "" )

overridevirtual

Paints this 2D graph with its current attributes.

Reimplemented from TObject.

Definition at line 1246 of file TGraph2D.cxx.

◆ Print()

void TGraph2D::Print ( Option_t * chopt = "" ) const

overridevirtual

Print 2D graph values.

Reimplemented from TObject.

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 1288 of file TGraph2D.cxx.

◆ Project()

TH1 * TGraph2D::Project ( Option_t * option = "x" ) const

Projects a 2-d graph into 1 or 2-d histograms depending on the option parameter.

option may contain a combination of the characters x,y,z:

option = "x" return the x projection into a TH1D histogram
option = "y" return the y projection into a TH1D histogram
option = "xy" return the x versus y projection into a TH2D histogram
option = "yx" return the y versus x projection into a TH2D histogram

Definition at line 1305 of file TGraph2D.cxx.

◆ RemovePoint()

Int_t TGraph2D::RemovePoint ( Int_t ipoint )

Deletes point number ipoint.

Definition at line 1392 of file TGraph2D.cxx.

◆ SavePrimitive()

void TGraph2D::SavePrimitive	(	std::ostream &	out,
		Option_t *	option = `""`
	)

overridevirtual

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

Reimplemented from TObject.

Definition at line 1428 of file TGraph2D.cxx.

◆ Scale()

void TGraph2D::Scale	(	Double_t	c1 = `1.`,
		Option_t *	option = `"z"`
	)

virtual

Multiply the values of a TGraph2D by a constant c1.

If option contains "x" the x values are scaled If option contains "y" the y values are scaled If option contains "z" the z values are scaled If option contains "xyz" all three x, y and z values are scaled

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 1482 of file TGraph2D.cxx.

◆ Set()

void TGraph2D::Set ( Int_t n )

virtual

Set number of points in the 2D graph.

Existing coordinates are preserved. New coordinates above fNpoints are preset to 0.

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 1504 of file TGraph2D.cxx.

◆ SetDirectory()

void TGraph2D::SetDirectory ( TDirectory * dir )

virtual

By default when an 2D graph is created, it is added to the list of 2D graph objects in the current directory in memory.

This method removes reference to this 2D graph from current directory and add reference to new directory dir. dir can be 0 in which case the 2D graph does not belong to any directory.

Definition at line 1520 of file TGraph2D.cxx.

◆ SetHistogram()

void TGraph2D::SetHistogram	(	TH2 *	h,
		Option_t *	option = `""`
	)

virtual

Sets the histogram to be filled.

If the 2D graph needs to be save in a TFile the following set should be followed to read it back:

Create TGraph2D
Call g->SetHistogram(h), and do whatever you need to do
Save g and h to the TFile, exit
Open the TFile, retrieve g and h
Call h->SetDirectory(0)
Call g->SetHistogram(h) again
Carry on as normal

By default use the new interpolation routine based on Triangles If the option "old" the old interpolation is used

Definition at line 1544 of file TGraph2D.cxx.

◆ SetMargin()

void TGraph2D::SetMargin ( Double_t m = 0.1 )

Sets the extra space (in %) around interpolated area for the 2D histogram.

Definition at line 1561 of file TGraph2D.cxx.

◆ SetMarginBinsContent()

void TGraph2D::SetMarginBinsContent ( Double_t z = 0. )

Sets the histogram bin height for points lying outside the TGraphDelaunay convex hull ie: the bins in the margin.

Definition at line 1581 of file TGraph2D.cxx.

◆ SetMaximum()

void TGraph2D::SetMaximum ( Double_t maximum = -1111 )

Set maximum.

Definition at line 1595 of file TGraph2D.cxx.

◆ SetMaxIter()

void TGraph2D::SetMaxIter ( Int_t n = 100000 )

inline

Definition at line 160 of file TGraph2D.h.

◆ SetMinimum()

void TGraph2D::SetMinimum ( Double_t minimum = -1111 )

Set minimum.

Definition at line 1606 of file TGraph2D.cxx.

◆ SetName()

void TGraph2D::SetName ( const char * name )

overridevirtual

Changes the name of this 2D graph.

Reimplemented from TNamed.

Definition at line 1617 of file TGraph2D.cxx.

◆ SetNameTitle()

void TGraph2D::SetNameTitle	(	const char *	name,
		const char *	title
	)

overridevirtual

Change the name and title of this 2D graph.

Reimplemented from TNamed.

Definition at line 1631 of file TGraph2D.cxx.

◆ SetNpx()

void TGraph2D::SetNpx ( Int_t npx = 40 )

Sets the number of bins along X used to draw the function.

Definition at line 1645 of file TGraph2D.cxx.

◆ SetNpy()

void TGraph2D::SetNpy ( Int_t npx = 40 )

Sets the number of bins along Y used to draw the function.

Definition at line 1667 of file TGraph2D.cxx.

◆ SetPoint()

void TGraph2D::SetPoint	(	Int_t	n,
		Double_t	x,
		Double_t	y,
		Double_t	z
	)

virtual

Sets point number n.

If n is greater than the current size, the arrays are automatically extended.

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 1691 of file TGraph2D.cxx.

◆ SetTitle()

void TGraph2D::SetTitle ( const char * title = "" )

overridevirtual

Sets the 2D graph title.

This method allows to change the global title and the axis' titles of a 2D graph. If g is the 2D graph one can do:

g->SetTitle("Graph title; X axis title; Y axis title; Z axis title");

Reimplemented from TNamed.

Definition at line 1738 of file TGraph2D.cxx.

◆ Streamer()

void TGraph2D::Streamer ( TBuffer & b )

overridevirtual

Stream a class object.

Reimplemented from TObject.

Reimplemented in TGraph2DAsymmErrors, and TGraph2DErrors.

Definition at line 1748 of file TGraph2D.cxx.

◆ StreamerNVirtual()

void TGraph2D::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 169 of file TGraph2D.h.

Member Data Documentation

◆ fDelaunay

TObject* TGraph2D::fDelaunay

protected

! Pointer to Delaunay interpolator object

Definition at line 59 of file TGraph2D.h.

◆ fDirectory

TDirectory* TGraph2D::fDirectory

protected

!Pointer to directory holding this 2D graph

Definition at line 60 of file TGraph2D.h.

◆ fFunctions

TList* TGraph2D::fFunctions

protected

Pointer to list of functions (fits and user)

Definition at line 57 of file TGraph2D.h.

◆ fHistogram

TH2D* TGraph2D::fHistogram

protected

!2D histogram of z values linearly interpolated on the triangles

Definition at line 58 of file TGraph2D.h.

◆ fMargin

Double_t TGraph2D::fMargin

protected

Extra space (in %) around interpolated area for fHistogram.

Definition at line 55 of file TGraph2D.h.

◆ fMaximum

Double_t TGraph2D::fMaximum

protected

Maximum value for plotting along z.

Definition at line 54 of file TGraph2D.h.

◆ fMaxIter

Int_t TGraph2D::fMaxIter

protected

Maximum number of iterations to find Delaunay triangles.

Definition at line 48 of file TGraph2D.h.

◆ fMinimum

Double_t TGraph2D::fMinimum

protected

Minimum value for plotting along z.

Definition at line 53 of file TGraph2D.h.

◆ fNpoints

Int_t TGraph2D::fNpoints

protected

Number of points in the data set.

Definition at line 45 of file TGraph2D.h.

◆ fNpx

Int_t TGraph2D::fNpx

protected

Number of bins along X in fHistogram.

Definition at line 46 of file TGraph2D.h.

◆ fNpy

Int_t TGraph2D::fNpy

protected

Number of bins along Y in fHistogram.

Definition at line 47 of file TGraph2D.h.

◆ fPainter

TVirtualHistPainter* TGraph2D::fPainter

protected

!Pointer to histogram painter

Definition at line 61 of file TGraph2D.h.

◆ fSize

Int_t TGraph2D::fSize

protected

!Real size of fX, fY and fZ

Definition at line 49 of file TGraph2D.h.

◆ fUserHisto

Bool_t TGraph2D::fUserHisto

private

Definition at line 67 of file TGraph2D.h.

◆ fX

Double_t* TGraph2D::fX

protected

[fNpoints]

Definition at line 50 of file TGraph2D.h.

◆ fY

Double_t* TGraph2D::fY

protected

[fNpoints] Data set to be plotted

Definition at line 51 of file TGraph2D.h.

◆ fZ

Double_t* TGraph2D::fZ

protected

[fNpoints]

Definition at line 52 of file TGraph2D.h.

◆ fZout

Double_t TGraph2D::fZout

protected

fHistogram bin height for points lying outside the interpolated area

Definition at line 56 of file TGraph2D.h.

Libraries for TGraph2D:

[legend]

The documentation for this class was generated from the following files:

hist/hist/inc/TGraph2D.h
hist/hist/src/TGraph2D.cxx

Creating a TGraph2D

Drawing options

Examples

SURF1 Example

Fitting Example

PCOL Example

Definition of the Delaunay triangulation (After B. Delaunay)

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Member Enumeration Documentation

◆ EStatusBits

Constructor & Destructor Documentation

◆ TGraph2D() [1/9]

◆ TGraph2D() [2/9]

◆ TGraph2D() [3/9]

◆ TGraph2D() [4/9]

◆ TGraph2D() [5/9]

◆ TGraph2D() [6/9]

◆ TGraph2D() [7/9]

◆ TGraph2D() [8/9]

◆ TGraph2D() [9/9]

◆ ~TGraph2D()

Member Function Documentation

◆ AddPoint()

◆ Browse()

◆ Build()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ Clear()

◆ CreateInterpolator()

◆ DeclFileName()

◆ DirectoryAutoAdd()

◆ DistancetoPrimitive()

◆ Draw()

◆ ExecuteEvent()

◆ FindObject() [1/2]

◆ FindObject() [2/2]

◆ Fit() [1/2]

◆ Fit() [2/2]

◆ FitPanel()

◆ GetContourList()

◆ GetDirectory()

◆ GetErrorX()

◆ GetErrorY()

◆ GetErrorZ()

◆ GetEX()

◆ GetEXhigh()

◆ GetEXlow()

◆ GetEY()

◆ GetEYhigh()

◆ GetEYlow()

◆ GetEZ()

◆ GetEZhigh()

◆ GetEZlow()

◆ GetHistogram()

◆ GetListOfFunctions()

◆ GetMargin()

◆ GetMaximum()

◆ GetMinimum()

◆ GetN()

◆ GetNpx()

◆ GetNpy()

◆ GetPoint()

◆ GetX()

◆ GetXaxis()

◆ GetXmax()

◆ GetXmaxE()

◆ GetXmin()

◆ GetXminE()

◆ GetY()

◆ GetYaxis()

◆ GetYmax()

◆ GetYmaxE()