#include "TCanvas.h"
#include "TPad.h"
#include "TMultiGraph.h"
#include "TGraph.h"
#include "TGraphErrors.h"
#include "TAxis.h"
#include "TLegend.h"
#include "TLatex.h"
#include "TROOT.h"
#include <cstdlib> 
void mulgr() {
   
   gStyle->SetOptFit();
   const char *datain = "C:/data.txt";
   const char *dataout = "C:/simulazione/plot.pdf";

   TCanvas *c01 = new TCanvas("c01","multigraph",1280,1024);
   //c01->SetGrid();
	TMultiGraph *mg = new TMultiGraph();
   float offx=1.3;
   float offy=1.3;
   float margr=0.08;
   float w=3;
   float margl=0.12;
   float line=2;
   gPad->SetLeftMargin(margl);
   gPad->SetRightMargin(margr);
   TPaveText *t=new TPaveText(0.7,0.15,0.75,0.2,"brNDC");
   TGraphErrors *gr1 = new TGraphErrors(datain,"%lg %lg %*lg");
   gr1->SetMarkerColor(kBlue);
   gr1->SetLineColor(kBlue);
   gr1->SetMarkerStyle(3);
   gr1->SetMarkerSize(1.3);
   gr1->SetLineWidth(line);
   gr1->SetDrawOption("AP");
   mg->Add(gr1);
   TGraphErrors *gr2 = new TGraphErrors(datain,"%lg %*lg %lg");
   gr2->SetMarkerColor(kRed);
   gr2->SetLineColor(kRed);
   gr2->SetMarkerStyle(5);
   gr2->SetMarkerSize(1.3);
   gr2->SetLineWidth(line);
   gr2->SetDrawOption("P");
   mg->Add(gr2);
   mg->Draw("LP");
   c01->Modified();
   c01->Update();
   mg->SetTitle("Graph");
   mg->GetXaxis()->SetTitle("x");
   mg->GetYaxis()->SetTitle("y");
   mg->GetYaxis()->SetTitleOffset(offy);
   mg->GetXaxis()->SetTitleOffset(offx);
   c01->Modified();
   c01->Update();
   TLegend* leg = new TLegend(0.15, 0.75, .25, .85);
   leg->SetHeader("Legend");
   leg->SetNColumns(1);
   leg->AddEntry(gr1, "gr1", "AP");
   leg->AddEntry(gr2, "gr2", "P");  
   leg->Draw();
   gPad->Update();
    gPad->Update();
    t->AddText("Text");
    t->Draw();
   gPad->Update();
   c01->Print(dataout);

}