TGraphErrors


class description - source file - inheritance tree

class TGraphErrors : public TGraph


    public:
TGraphErrors TGraphErrors() TGraphErrors TGraphErrors(Int_t n, Float_t* x = 0, Float_t* y = 0, Float_t* ex = 0, Float_t* ey = 0) TGraphErrors TGraphErrors(TGraphErrors&) virtual void ~TGraphErrors() TClass* Class() virtual void ComputeRange(Float_t& xmin, Float_t& ymin, Float_t& xmax, Float_t& ymax) virtual Float_t GetErrorX(Int_t bin) virtual Float_t GetErrorY(Int_t bin) Float_t* GetEX() Float_t* GetEY() virtual TClass* IsA() const virtual void Paint(Option_t* chopt) virtual void Print(Option_t* chopt) virtual void SavePrimitive(ofstream& out, Option_t* option) virtual void SetPoint(Int_t i, Float_t x, Float_t y) virtual void SetPointError(Int_t i, Float_t ex, Float_t ey) virtual void ShowMembers(TMemberInspector& insp, char* parent) virtual void Streamer(TBuffer& b)

Data Members

protected:
Float_t* fEX [fNpoints] array of X errors Float_t* fEY [fNpoints] array of Y errors

Class Description

   A TGraphErrors is a TGraph with error bars.
   The various format options to draw a TGraphErrors are explained in
     TGraphErrors::Paint.

  The picture below has been generated by the following macro:
------------------------------------------------------------------------
{
   gROOT->Reset();
   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);

   Int_t n = 10;
   Float_t x[n]  = {-0.22, 0.05, 0.25, 0.35, 0.5, 0.61,0.7,0.85,0.89,0.95};
   Float_t y[n]  = {1,2.9,5.6,7.4,9,9.6,8.7,6.3,4.5,1};
   Float_t ex[n] = {.05,.1,.07,.07,.04,.05,.06,.07,.08,.05};
   Float_t ey[n] = {.8,.7,.6,.5,.4,.4,.5,.6,.7,.8};
   gr = new TGraphErrors(n,x,y,ex,ey);
   gr->SetTitle("TGraphErrors Example");
   gr->SetMarkerColor(4);
   gr->SetMarkerStyle(21);
   gr->Draw("ALP");

   c1->Update();
}

/*

*/



TGraphErrors(): TGraph()
*-*-*-*-*-*-*-*-*-*-*TGraphErrors default constructor*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ================================

TGraphErrors(Int_t n, Float_t *x, Float_t *y, Float_t *ex, Float_t *ey) : TGraph(n,x,y)
*-*-*-*-*-*-*-*-*-*-*TGraphErrors normal constructor*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ===============================

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

~TGraphErrors()
*-*-*-*-*-*-*-*-*-*-*TGraphErrors default destructor*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ===============================

void ComputeRange(Float_t &xmin, Float_t &ymin, Float_t &xmax, Float_t &ymax)

Float_t GetErrorX(Int_t i)
    This function is called by GraphFitChisquare.
    It returns the error along X at point i.

Float_t GetErrorY(Int_t i)
    This function is called by GraphFitChisquare.
    It returns the error along Y at point i.

void Paint(Option_t *option)
*-*-*-*-*-*-*-*-*Draw this TGraphErrors with its current attributes*-*-*-*-*
*-*              ==================================================

void Print(Option_t *)
*-*-*-*-*-*-*-*-*-*-*Print graph and errors values*-*-*-*-*-*-*-*-*-*-*-*
*-*                  =============================


void SavePrimitive(ofstream &out, Option_t *option)
 Save primitive as a C++ statement(s) on output stream out

void SetPoint(Int_t i, Float_t x, Float_t y)
*-*-*-*-*-*-*-*-*-*-*Set x and y values for point number i*-*-*-*-*-*-*-*-*
*-*                  =====================================

void SetPointError(Int_t i, Float_t ex, Float_t ey)
*-*-*-*-*-*-*-*-*-*-*Set ex and ey values for point number i*-*-*-*-*-*-*-*
*-*                  =======================================

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



Inline Functions


            Float_t* GetEX()
            Float_t* GetEY()
             TClass* Class()
             TClass* IsA() const
                void ShowMembers(TMemberInspector& insp, char* parent)
        TGraphErrors TGraphErrors(TGraphErrors&)


Author: Rene Brun 15/09/96
Last update: 2.23/12 22/01/2000 17.46.26 by Rene Brun
Copyright (c) 1995-1999, The ROOT System, All rights reserved. *


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