A TGraphErrors is a TGraph with error bars.

The TGraphErrors painting is performed thanks to the TGraphPainter class. All details about the various painting options are given in this class.

The picture below gives an example:

{
   auto c1 = new TCanvas("c1","A Simple Graph with error bars",200,10,700,500);
   c1->SetFillColor(42);
   c1->SetGrid();
   c1->GetFrame()->SetFillColor(21);
   c1->GetFrame()->SetBorderSize(12);
   const Int_t n = 10;
   Double_t x[n]  = {-0.22, 0.05, 0.25, 0.35, 0.5, 0.61,0.7,0.85,0.89,0.95};
   Double_t y[n]  = {1,2.9,5.6,7.4,9,9.6,8.7,6.3,4.5,1};
   Double_t ex[n] = {.05,.1,.07,.07,.04,.05,.06,.07,.08,.05};
   Double_t ey[n] = {.8,.7,.6,.5,.4,.4,.5,.6,.7,.8};
   auto gr = new TGraphErrors(n,x,y,ex,ey);
   gr->SetTitle("TGraphErrors Example");
   gr->SetMarkerColor(4);
   gr->SetMarkerStyle(21);
   gr->Draw("ALP");
}

Definition at line 26 of file TGraphErrors.h.

Public Member Functions
	TGraphErrors ()
	TGraphErrors default constructor.

	TGraphErrors (const char filename, const char format="%lg %lg %lg %lg", Option_t *option="")
	GraphErrors constructor reading input from `filename`.

	TGraphErrors (const TGraphErrors &gr)
	TGraphErrors copy constructor.

	TGraphErrors (const TH1 *h)
	TGraphErrors constructor importing its parameters from the TH1 object passed as argument.

	TGraphErrors (const TVectorD &vx, const TVectorD &vy, const TVectorD &vex, const TVectorD &vey)
	Constructor with four vectors of doubles in input.

	TGraphErrors (const TVectorF &vx, const TVectorF &vy, const TVectorF &vex, const TVectorF &vey)
	Constructor with four vectors of floats in input.

	TGraphErrors (Int_t n)
	TGraphErrors normal constructor.

	TGraphErrors (Int_t n, const Double_t x, const Double_t y, const Double_t ex=nullptr, const Double_t ey=nullptr)
	TGraphErrors normal constructor.

	TGraphErrors (Int_t n, const Float_t x, const Float_t y, const Float_t ex=nullptr, const Float_t ey=nullptr)
	TGraphErrors normal constructor.

	~TGraphErrors () override
	TGraphErrors default destructor.

virtual void	AddPointError (Double_t x, Double_t y, Double_t ex=0., Double_t ey=0.)
	Add a point with errorbars to the graph.

void	Apply (TF1 *f) override
	Apply function to all the data points \( y = f(x,y) \).

virtual void	ApplyX (TF1 *f)
	Apply function to all the data points \( x = f(x,y) \).

void	ComputeRange (Double_t &xmin, Double_t &ymin, Double_t &xmax, Double_t &ymax) const override
	Compute range.

Double_t	GetErrorX (Int_t bin) const override
	It returns the error along X at point `i`.

Double_t	GetErrorXhigh (Int_t bin) const override
	It returns the error along X at point `i`.

Double_t	GetErrorXlow (Int_t bin) const override
	It returns the error along X at point `i`.

Double_t	GetErrorY (Int_t bin) const override
	It returns the error along Y at point `i`.

Double_t	GetErrorYhigh (Int_t bin) const override
	It returns the error along Y at point `i`.

Double_t	GetErrorYlow (Int_t bin) const override
	It returns the error along Y at point `i`.

Double_t *	GetEX () const override

Double_t *	GetEY () const override

TClass *	IsA () const override

Int_t	Merge (TCollection *list) override
	Adds all graphs with errors from the collection to this graph.

TGraphErrors &	operator= (const TGraphErrors &gr)
	TGraphErrors assignment operator.

void	Print (Option_t *chopt="") const override
	Print graph and errors values.

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

void	Scale (Double_t c1=1., Option_t *option="y") override
	Multiply the values and errors of a TGraphErrors by a constant c1.

virtual void	SetPointError (Double_t ex, Double_t ey)
	Set `ex` and `ey` values for point pointed by the mouse.

virtual void	SetPointError (Int_t i, Double_t ex, Double_t ey)
	Set `ex` and `ey` values for point number i.

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

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TGraph
	TGraph ()
	Graph default constructor.

	TGraph (const char filename, const char format="%lg %lg", Option_t *option="")
	Graph constructor reading input from filename.

	TGraph (const TF1 f, Option_t option="")
	Graph constructor importing its parameters from the TF1 object passed as argument.

	TGraph (const TGraph &gr)
	Copy constructor for this graph.

	TGraph (const TH1 *h)
	Graph constructor importing its parameters from the TH1 object passed as argument.

	TGraph (const TVectorD &vx, const TVectorD &vy)
	Graph constructor with two vectors of doubles in input A graph is build with the X coordinates taken from vx and Y coord from vy The number of points in the graph is the minimum of number of points in vx and vy.

	TGraph (const TVectorF &vx, const TVectorF &vy)
	Graph constructor with two vectors of floats in input A graph is build with the X coordinates taken from vx and Y coord from vy The number of points in the graph is the minimum of number of points in vx and vy.

	TGraph (Int_t n)
	Constructor with only the number of points set the arrays x and y will be set later.

	TGraph (Int_t n, const Double_t x, const Double_t y)
	Graph normal constructor with doubles.

	TGraph (Int_t n, const Double_t *y, Double_t start=0., Double_t step=1.)
	Default X-Points constructor.

	TGraph (Int_t n, const Float_t x, const Float_t y)
	Graph normal constructor with floats.

	TGraph (Int_t n, const Int_t x, const Int_t y)
	Graph normal constructor with ints.

	~TGraph () override
	Graph default destructor.

virtual void	Add (TF1 *f, Double_t c1=1)
	Performs the operation: `y = y + c1*f(x,y)` Errors are not recalculated.

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

void	Browse (TBrowser *b) override
	Browse.

virtual Double_t	Chisquare (TF1 f1, Option_t option="") const
	Return the chisquare of this graph with respect to f1.

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

void	Draw (Option_t *chopt="") override
	Draw this graph with its current attributes.

virtual void	DrawGraph (Int_t n, const Double_t x=nullptr, const Double_t y=nullptr, Option_t *option="")
	Draw this graph with new attributes.

virtual void	DrawGraph (Int_t n, const Float_t x, const Float_t y, Option_t *option="")
	Draw this graph with new attributes.

virtual void	DrawGraph (Int_t n, const Int_t x, const Int_t y, Option_t *option="")
	Draw this graph with new attributes.

virtual void	DrawPanel ()
	Display a panel with all graph drawing options.

virtual Double_t	Eval (Double_t x, TSpline spline=nullptr, Option_t option="") const
	Interpolate points in this graph at x using a TSpline.

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

virtual void	Expand (Int_t newsize)
	If array sizes <= newsize, expand storage to 2*newsize.

virtual void	Expand (Int_t newsize, Int_t step)
	If graph capacity is less than newsize points then make array sizes equal to least multiple of step to contain newsize points.

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="", Axis_t xmin=0, Axis_t xmax=0)
	Fit this graph with function with name `fname`.

virtual TFitResultPtr	Fit (TF1 f1, Option_t option="", Option_t *goption="", Axis_t xmin=0, Axis_t xmax=0)
	Fit this graph with function f1.

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

virtual Double_t	GetCorrelationFactor () const
	Return graph correlation factor.

virtual Double_t	GetCovariance () const
	Return covariance of vectors x,y.

Bool_t	GetEditable () const
	Return kTRUE if kNotEditable bit is not set, kFALSE otherwise.

virtual Double_t *	GetEXhigh () const

virtual Double_t *	GetEXhighd () const

virtual Double_t *	GetEXlow () const

virtual Double_t *	GetEXlowd () const

virtual Double_t *	GetEYhigh () const

virtual Double_t *	GetEYhighd () const

virtual Double_t *	GetEYlow () const

virtual Double_t *	GetEYlowd () const

TF1 *	GetFunction (const char *name) const
	Return pointer to function with name.

virtual TH1F *	GetHistogram () const
	Returns a pointer to the histogram used to draw the axis Takes into account the two following cases.

TList *	GetListOfFunctions () const

Double_t	GetMaximum () const

Int_t	GetMaxSize () const

virtual Double_t	GetMean (Int_t axis=1) const
	Return mean value of X (axis=1) or Y (axis=2)

Double_t	GetMinimum () const

Int_t	GetN () const

char *	GetObjectInfo (Int_t px, Int_t py) const override
	Implementation to get information on point of graph at cursor position Adapted from class TH1.

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

virtual Double_t	GetPointX (Int_t i) const
	Get x value for point i.

virtual Double_t	GetPointY (Int_t i) const
	Get y value for point i.

virtual Double_t	GetRMS (Int_t axis=1) const
	Return RMS of X (axis=1) or Y (axis=2)

Double_t *	GetX () const

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

Double_t *	GetY () const

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

virtual void	InitExpo (Double_t xmin=0, Double_t xmax=0)
	Compute Initial values of parameters for an exponential.

virtual void	InitGaus (Double_t xmin=0, Double_t xmax=0)
	Compute Initial values of parameters for a gaussian.

virtual void	InitPolynom (Double_t xmin=0, Double_t xmax=0)
	Compute Initial values of parameters for a polynom.

virtual Int_t	InsertPoint ()
	Insert a new point at the mouse position.

virtual void	InsertPointBefore (Int_t ipoint, Double_t x, Double_t y)
	Insert a new point with coordinates (x,y) before the point number `ipoint`.

virtual Double_t	Integral (Int_t first=0, Int_t last=-1) const
	Integrate the TGraph data within a given (index) range.

virtual Bool_t	IsEditable () const

virtual Bool_t	IsHighlight () const

virtual Int_t	IsInside (Double_t x, Double_t y) const
	Return 1 if the point (x,y) is inside the polygon defined by the graph vertices 0 otherwise.

virtual void	LeastSquareFit (Int_t m, Double_t *a, Double_t xmin=0, Double_t xmax=0)
	Least squares polynomial fitting without weights.

virtual void	LeastSquareLinearFit (Int_t n, Double_t &a0, Double_t &a1, Int_t &ifail, Double_t xmin=0, Double_t xmax=0)
	Least square linear fit without weights.

virtual void	MovePoints (Double_t dx, Double_t dy, Bool_t logx=kFALSE, Bool_t logy=kFALSE)
	Move all graph points on specified values dx,dy If log argument specified, calculation done in logarithmic scale like: new_value = exp( log(old_value) + delta );.

TGraph &	operator= (const TGraph &)
	Equal operator for this graph.

void	Paint (Option_t *chopt="") override
	Draw this graph with its current attributes.

void	PaintGraph (Int_t npoints, const Double_t x, const Double_t y, Option_t *chopt)
	Draw the (x,y) as a graph.

void	PaintGrapHist (Int_t npoints, const Double_t x, const Double_t y, Option_t *chopt)
	Draw the (x,y) as a histogram.

virtual void	PaintStats (TF1 *fit)
	Draw the stats.

void	RecursiveRemove (TObject *obj) override
	Recursively remove object from the list of functions.

virtual Int_t	RemovePoint ()
	Delete point close to the mouse position Returns index of removed point (or -1 if nothing was changed)

virtual Int_t	RemovePoint (Int_t ipoint)
	Delete point number ipoint Returns index of removed point (or -1 if nothing was changed)

void	SaveAs (const char filename="graph", Option_t option="") const override
	Save the graph as .csv, .tsv or .txt.

virtual void	Set (Int_t n)
	Set number of points in the graph Existing coordinates are preserved New coordinates above fNpoints are preset to 0.

virtual void	SetEditable (Bool_t editable=kTRUE)
	if editable=kFALSE, the graph cannot be modified with the mouse by default a TGraph is editable

virtual void	SetHighlight (Bool_t set=kTRUE)
	Set highlight (enable/disable) mode for the graph by default highlight mode is disable.

virtual void	SetHistogram (TH1F *h)

virtual void	SetMaximum (Double_t maximum=-1111)
	Set the maximum of the graph.

virtual void	SetMinimum (Double_t minimum=-1111)
	Set the minimum of the graph.

void	SetName (const char *name="") override
	Set graph name.

void	SetNameTitle (const char name="", const char title="") override
	Set graph name and title.

virtual void	SetOption (Option_t *option=" ")

virtual void	SetPoint (Int_t i, Double_t x, Double_t y)
	Set x and y values for point number i.

virtual void	SetPointX (Int_t i, Double_t x)
	Set x value for point i.

virtual void	SetPointY (Int_t i, Double_t y)
	Set y value for point i.

virtual void	SetStats (Bool_t stats=kTRUE)
	Set statistics option on/off.

void	SetTitle (const char *title="") override
	Change (i.e.

virtual void	Sort (Bool_t(greater)(const TGraph , Int_t, Int_t)=&TGraph::CompareX, Bool_t ascending=kTRUE, Int_t low=0, Int_t high=-1111)
	Sorts the points of this TGraph using in-place quicksort (see e.g.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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

void	Zero (Int_t &k, Double_t AZ, Double_t BZ, Double_t E2, Double_t &X, Double_t &Y, Int_t maxiterations)
	Find zero of a continuous function.

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 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.

void	ResetBit (UInt_t f)

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	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 Int_t	CalculateScanfFields (const char *fmt)
	Calculate scan fields.

static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

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

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static Bool_t	CompareArg (const TGraph *gr, Int_t left, Int_t right)
	Return kTRUE if point number "left"'s argument (angle with respect to positive x-axis) is bigger than that of point number "right".

static Bool_t	CompareRadius (const TGraph *gr, Int_t left, Int_t right)
	Return kTRUE if point number "left"'s distance to origin is bigger than that of point number "right".

static Bool_t	CompareX (const TGraph *gr, Int_t left, Int_t right)
	Return kTRUE if fX[left] > fX[right]. Can be used by Sort.

static Bool_t	CompareY (const TGraph *gr, Int_t left, Int_t right)
	Return kTRUE if fY[left] > fY[right]. Can be used by Sort.

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
Double_t **	Allocate (Int_t size) override
	Allocate internal data structures for `newsize` points.

void	CopyAndRelease (Double_t **newarrays, Int_t ibegin, Int_t iend, Int_t obegin) override
	Copy and release.

Bool_t	CopyPoints (Double_t **arrays, Int_t ibegin, Int_t iend, Int_t obegin) override
	Copy errors from `fEX` and `fEY` to `arrays[0]` and `arrays[1]` or to `fEX` and `fEY` if `arrays == 0` and `ibegin != iend`.

Bool_t	CtorAllocate ()
	Constructor allocate.

Bool_t	DoMerge (const TGraph *g) override
	Protected function to perform the merge operation of a graph with errors.

void	FillZero (Int_t begin, Int_t end, Bool_t from_ctor=kTRUE) override
	Set zero values for point arrays in the range `[begin, end]`.

void	SwapPoints (Int_t pos1, Int_t pos2) override
	Swap points.

void	UpdateArrays (const std::vector< Int_t > &sorting_indices, Int_t numSortedPoints, Int_t low) override
	Update the fX, fY, fEX, and fEY arrays with the sorted values.

Protected Member Functions inherited from TGraph
Double_t **	AllocateArrays (Int_t Narrays, Int_t arraySize)
	Allocate arrays.

Bool_t	CtorAllocate ()
	In constructors set fNpoints than call this method.

Double_t **	ExpandAndCopy (Int_t size, Int_t iend)
	if size > fMaxSize allocate new arrays of 2*size points and copy iend first points.

TString	SaveArray (std::ostream &out, const char suffix, Int_t frameNumber, Double_t arr)
	Save array as C++ code Returns name of created array.

void	SaveHistogramAndFunctions (std::ostream &out, const char varname, Int_t &frameNumber, Option_t option)
	Save histogram and list of functions of TGraph as C++ statement Used in all TGraph-derived classes.

Double_t **	ShrinkAndCopy (Int_t size, Int_t iend)
	if size*2 <= fMaxSize allocate new arrays of size points, copy points [0,oend).

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
Double_t *	fEX {nullptr}
	[fNpoints] array of X errors

Double_t *	fEY {nullptr}
	[fNpoints] array of Y errors

Protected Attributes inherited from TGraph
TList *	fFunctions
	Pointer to list of functions (fits and user)

TH1F *	fHistogram
	Pointer to histogram used for drawing axis.

Double_t	fMaximum
	Maximum value for plotting along y.

Int_t	fMaxSize
	!Current dimension of arrays fX and fY

Double_t	fMinimum
	Minimum value for plotting along y.

Int_t	fNpoints
	Number of points <= fMaxSize.

TString	fOption
	Options used for drawing the graph.

Double_t *	fX
	[fNpoints] array of X points

Double_t *	fY
	[fNpoints] array of Y points

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.

Additional Inherited Members
Public Types inherited from TGraph
enum	EStatusBits { kNoStats = (1ULL << ( 9 )) , kClipFrame = (1ULL << ( 10 )) , kResetHisto = (1ULL << ( 17 )) , kNotEditable = (1ULL << ( 18 )) , kIsSortedX = (1ULL << ( 19 )) , kIsHighlight = (1ULL << ( 20 )) }

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 )) }

Static Protected Member Functions inherited from TGraph
static void	SwapValues (Double_t *arr, Int_t pos1, Int_t pos2)
	Swap values.

#include <TGraphErrors.h>

Inheritance diagram for TGraphErrors:

[legend]

Constructor & Destructor Documentation

◆ TGraphErrors() [1/9]

TGraphErrors::TGraphErrors ( )

TGraphErrors default constructor.

Definition at line 69 of file TGraphErrors.cxx.

◆ TGraphErrors() [2/9]

TGraphErrors::TGraphErrors ( Int_t n )

TGraphErrors normal constructor.

the arrays are preset to zero

Definition at line 80 of file TGraphErrors.cxx.

◆ TGraphErrors() [3/9]

TGraphErrors::TGraphErrors	(	Int_t	n,
		const Float_t *	x,
		const Float_t *	y,
		const Float_t *	ex = `nullptr`,
		const Float_t *	ey = `nullptr`
	)

TGraphErrors normal constructor.

if ex or ey are null, the corresponding arrays are preset to zero

Definition at line 93 of file TGraphErrors.cxx.

◆ TGraphErrors() [4/9]

TGraphErrors::TGraphErrors	(	Int_t	n,
		const Double_t *	x,
		const Double_t *	y,
		const Double_t *	ex = `nullptr`,
		const Double_t *	ey = `nullptr`
	)

TGraphErrors normal constructor.

if ex or ey are null, the corresponding arrays are preset to zero

Definition at line 112 of file TGraphErrors.cxx.

◆ TGraphErrors() [5/9]

TGraphErrors::TGraphErrors	(	const TVectorF &	vx,
		const TVectorF &	vy,
		const TVectorF &	vex,
		const TVectorF &	vey
	)

Constructor with four vectors of floats in input.

A grapherrors is built with the X coordinates taken from vx and Y coord from vy and the errors from vectors vex and vey. The number of points in the graph is the minimum of number of points in vx and vy.

Definition at line 133 of file TGraphErrors.cxx.

◆ TGraphErrors() [6/9]

TGraphErrors::TGraphErrors	(	const TVectorD &	vx,
		const TVectorD &	vy,
		const TVectorD &	vex,
		const TVectorD &	vey
	)

Constructor with four vectors of doubles in input.

A grapherrors is built with the X coordinates taken from vx and Y coord from vy and the errors from vectors vex and vey. The number of points in the graph is the minimum of number of points in vx and vy.

Definition at line 154 of file TGraphErrors.cxx.

◆ TGraphErrors() [7/9]

TGraphErrors::TGraphErrors ( const TGraphErrors & gr )

TGraphErrors copy constructor.

Definition at line 170 of file TGraphErrors.cxx.

◆ TGraphErrors() [8/9]

TGraphErrors::TGraphErrors ( const TH1 * h )

TGraphErrors constructor importing its parameters from the TH1 object passed as argument.

Definition at line 204 of file TGraphErrors.cxx.

◆ TGraphErrors() [9/9]

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

GraphErrors constructor reading input from filename.

filename is assumed to contain at least 2 columns of numbers

Convention for format (default="%lg %lg %lg %lg")

format = lg lg read only 2 first columns into X,Y
format = lg lg lg read only 3 first columns into X,Y and EY
format = lg lg lg lg read only 4 first columns into X,Y,EX,EY.

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. In case a delimiter is specified, the format "%lg %lg %lg" will read X,Y,EX.

Definition at line 235 of file TGraphErrors.cxx.

◆ ~TGraphErrors()

TGraphErrors::~TGraphErrors ( )

override

TGraphErrors default destructor.

Definition at line 368 of file TGraphErrors.cxx.

Member Function Documentation

◆ AddPointError()

void TGraphErrors::AddPointError	(	Double_t	x,
		Double_t	y,
		Double_t	ex = `0.`,
		Double_t	ey = `0.`
	)

virtual

Add a point with errorbars to the graph.

Definition at line 377 of file TGraphErrors.cxx.

◆ Allocate()

Double_t ** TGraphErrors::Allocate ( Int_t newsize )

inlineoverrideprotectedvirtual

Allocate internal data structures for newsize points.

Reimplemented from TGraph.

Definition at line 81 of file TGraphErrors.h.

◆ Apply()

void TGraphErrors::Apply ( TF1 * f )

overridevirtual

Apply function to all the data points \( y = f(x,y) \).

The error is calculated as \( ey=(f(x,y+ey)-f(x,y-ey))/2 \). This is the same as \( error(fy) = df/dy * ey \) for small errors.

For generic functions the symmetric errors might become non-symmetric and are averaged here. Use TGraphAsymmErrors if desired.

Error on \( x \) doesn't change.

function suggested/implemented by Miroslav Helbich helbi.nosp@m.ch@m.nosp@m.ail.d.nosp@m.esy..nosp@m.de

Reimplemented from TGraph.

Definition at line 396 of file TGraphErrors.cxx.

◆ ApplyX()

void TGraphErrors::ApplyX ( TF1 * f )

virtual

Apply function to all the data points \( x = f(x,y) \).

The error is calculated as \( ex=(f(x+ex,y)-f(x-ex,y))/2 \). This is the same as \( error(fx) = df/dx * ex \) for small errors.

For generic functions the symmetric errors might become non-symmetric and are averaged here. Use TGraphAsymmErrors if desired.

Error on \( y \) doesn't change.

Definition at line 426 of file TGraphErrors.cxx.

◆ CalculateScanfFields()

Int_t TGraphErrors::CalculateScanfFields ( const char * fmt )

static

Calculate scan fields.

Definition at line 449 of file TGraphErrors.cxx.

◆ Class()

static TClass * TGraphErrors::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TGraphErrors::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TGraphErrors::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 78 of file TGraphErrors.h.

◆ ComputeRange()

void TGraphErrors::ComputeRange	(	Double_t &	xmin,
		Double_t &	ymin,
		Double_t &	xmax,
		Double_t &	ymax
	)		const

overridevirtual

Compute range.

Reimplemented from TGraph.

Definition at line 480 of file TGraphErrors.cxx.

◆ CopyAndRelease()

void TGraphErrors::CopyAndRelease	(	Double_t **	newarrays,
		Int_t	ibegin,
		Int_t	iend,
		Int_t	obegin
	)

overrideprotectedvirtual

Copy and release.

Reimplemented from TGraph.

Definition at line 510 of file TGraphErrors.cxx.

◆ CopyPoints()

Bool_t TGraphErrors::CopyPoints	(	Double_t **	arrays,
		Int_t	ibegin,
		Int_t	iend,
		Int_t	obegin
	)

overrideprotectedvirtual

Copy errors from fEX and fEY to arrays[0] and arrays[1] or to fEX and fEY if arrays == 0 and ibegin != iend.

Reimplemented from TGraph.

Definition at line 532 of file TGraphErrors.cxx.

◆ CtorAllocate()

Bool_t TGraphErrors::CtorAllocate ( )

protected

Constructor allocate.

Note: This function should be called only from the constructor since it does not delete previously existing arrays.

Definition at line 557 of file TGraphErrors.cxx.

◆ DeclFileName()

static const char * TGraphErrors::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 78 of file TGraphErrors.h.

◆ DoMerge()

Bool_t TGraphErrors::DoMerge ( const TGraph * g )

overrideprotectedvirtual

Protected function to perform the merge operation of a graph with errors.

Reimplemented from TGraph.

Definition at line 573 of file TGraphErrors.cxx.

◆ FillZero()

void TGraphErrors::FillZero	(	Int_t	begin,
		Int_t	end,
		Bool_t	from_ctor = `kTRUE`
	)

overrideprotectedvirtual

Set zero values for point arrays in the range [begin, end].

Reimplemented from TGraph.

Definition at line 598 of file TGraphErrors.cxx.

◆ GetErrorX()

Double_t TGraphErrors::GetErrorX ( Int_t bin ) const

overridevirtual

It returns the error along X at point i.

Reimplemented from TGraph.

Definition at line 612 of file TGraphErrors.cxx.

◆ GetErrorXhigh()

Double_t TGraphErrors::GetErrorXhigh ( Int_t i ) const

overridevirtual

It returns the error along X at point i.

For TGraphErrors this method is the same as GetErrorX.

Reimplemented from TGraph.

Definition at line 635 of file TGraphErrors.cxx.

◆ GetErrorXlow()

Double_t TGraphErrors::GetErrorXlow ( Int_t i ) const

overridevirtual

It returns the error along X at point i.

For TGraphErrors this method is the same as GetErrorX.

Reimplemented from TGraph.

Definition at line 647 of file TGraphErrors.cxx.

◆ GetErrorY()

Double_t TGraphErrors::GetErrorY ( Int_t bin ) const

overridevirtual

It returns the error along Y at point i.

Reimplemented from TGraph.

Definition at line 623 of file TGraphErrors.cxx.

◆ GetErrorYhigh()

Double_t TGraphErrors::GetErrorYhigh ( Int_t i ) const

overridevirtual

It returns the error along Y at point i.

For TGraphErrors this method is the same as GetErrorY.

Reimplemented from TGraph.

Definition at line 659 of file TGraphErrors.cxx.

◆ GetErrorYlow()

Double_t TGraphErrors::GetErrorYlow ( Int_t i ) const

overridevirtual

It returns the error along Y at point i.

For TGraphErrors this method is the same as GetErrorY.

Reimplemented from TGraph.

Definition at line 671 of file TGraphErrors.cxx.

◆ GetEX()

Double_t * TGraphErrors::GetEX ( ) const

inlineoverridevirtual

Reimplemented from TGraph.

Definition at line 69 of file TGraphErrors.h.

◆ GetEY()

Double_t * TGraphErrors::GetEY ( ) const

inlineoverridevirtual

Reimplemented from TGraph.

Definition at line 70 of file TGraphErrors.h.

◆ IsA()

TClass * TGraphErrors::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TGraph.

Reimplemented in TGraphPolar.

Definition at line 78 of file TGraphErrors.h.

◆ Merge()

Int_t TGraphErrors::Merge ( TCollection * li )

overridevirtual

Adds all graphs with errors from the collection to this graph.

Returns the total number of points in the result or -1 in case of an error.

Reimplemented from TGraph.

Definition at line 682 of file TGraphErrors.cxx.

◆ operator=()

TGraphErrors & TGraphErrors::operator= ( const TGraphErrors & gr )

TGraphErrors assignment operator.

Definition at line 184 of file TGraphErrors.cxx.

◆ Print()

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

overridevirtual

Print graph and errors values.

Reimplemented from TGraph.

Definition at line 711 of file TGraphErrors.cxx.

◆ SavePrimitive()

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

overridevirtual

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

Reimplemented from TGraph.

Definition at line 722 of file TGraphErrors.cxx.

◆ Scale()

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

overridevirtual

Multiply the values and errors of a TGraphErrors by a constant c1.

If option contains "x" the x values and errors are scaled If option contains "y" the y values and errors are scaled If option contains "xy" both x and y values and errors are scaled

Reimplemented from TGraph.

Definition at line 752 of file TGraphErrors.cxx.

◆ SetPointError() [1/2]

void TGraphErrors::SetPointError	(	Double_t	ex,
		Double_t	ey
	)

virtual

Set ex and ey values for point pointed by the mouse.

Definition at line 769 of file TGraphErrors.cxx.

◆ SetPointError() [2/2]

void TGraphErrors::SetPointError	(	Int_t	i,
		Double_t	ex,
		Double_t	ey
	)

virtual

Set ex and ey values for point number i.

Definition at line 802 of file TGraphErrors.cxx.

◆ Streamer()

void TGraphErrors::Streamer ( TBuffer & b )

overridevirtual

Stream an object of class TGraphErrors.

Reimplemented from TGraph.

Reimplemented in TGraphPolar.

Definition at line 817 of file TGraphErrors.cxx.

◆ StreamerNVirtual()

void TGraphErrors::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 78 of file TGraphErrors.h.

◆ SwapPoints()

void TGraphErrors::SwapPoints	(	Int_t	pos1,
		Int_t	pos2
	)

overrideprotectedvirtual

Swap points.

Reimplemented from TGraph.

Definition at line 856 of file TGraphErrors.cxx.

◆ UpdateArrays()

void TGraphErrors::UpdateArrays	(	const std::vector< Int_t > &	sorting_indices,
		Int_t	numSortedPoints,
		Int_t	low
	)

overrideprotectedvirtual

Update the fX, fY, fEX, and fEY arrays with the sorted values.

Reimplemented from TGraph.

Definition at line 866 of file TGraphErrors.cxx.

Member Data Documentation

◆ fEX

Double_t* TGraphErrors::fEX {nullptr}

protected

[fNpoints] array of X errors

Definition at line 29 of file TGraphErrors.h.

◆ fEY

Double_t* TGraphErrors::fEY {nullptr}

protected

[fNpoints] array of Y errors

Definition at line 30 of file TGraphErrors.h.

Libraries for TGraphErrors:

[legend]

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

hist/hist/inc/TGraphErrors.h
hist/hist/src/TGraphErrors.cxx

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TGraphErrors() [1/9]

◆ TGraphErrors() [2/9]

◆ TGraphErrors() [3/9]

◆ TGraphErrors() [4/9]

◆ TGraphErrors() [5/9]

◆ TGraphErrors() [6/9]

◆ TGraphErrors() [7/9]

◆ TGraphErrors() [8/9]

◆ TGraphErrors() [9/9]

◆ ~TGraphErrors()

Member Function Documentation

◆ AddPointError()

◆ Allocate()

◆ Apply()

◆ ApplyX()

◆ CalculateScanfFields()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ ComputeRange()

◆ CopyAndRelease()

◆ CopyPoints()

◆ CtorAllocate()

◆ DeclFileName()

◆ DoMerge()

◆ FillZero()

◆ GetErrorX()

◆ GetErrorXhigh()

◆ GetErrorXlow()

◆ GetErrorY()

◆ GetErrorYhigh()

◆ GetErrorYlow()

◆ GetEX()

◆ GetEY()

◆ IsA()

◆ Merge()

◆ operator=()

◆ Print()

◆ SavePrimitive()

◆ Scale()

◆ SetPointError() [1/2]

◆ SetPointError() [2/2]

◆ Streamer()

◆ StreamerNVirtual()

◆ SwapPoints()

◆ UpdateArrays()

Member Data Documentation

◆ fEX

◆ fEY