#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 "TRatioPlot.h"
#include <cstdlib> 
void mulgr() {
   
   gStyle->SetOptFit();
   int YLabelSize=25;
   int XLabelSize=25;
   int YTitleSize=25;
   int XTitleSize=25;
   const char *datain = "C:/data.txt";
   const char *dataout = "C:/simulazione/plot.pdf";
   TCanvas *c01 = new TCanvas("c01","multigraph",1280,1024);
   gStyle->SetTitleSize(0.1,"t");
    TPad *pad1 = new TPad("pad1", "pad1", 0.0, 0.5, 1.0, 1.);
     pad1->SetGridx();         // Vertical grid
   pad1->Draw();             // Draw the upper pad: pad1
   pad1->cd();    
   //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(0.8,0.15,0.85,0.2,"brNDC");
   TGraphErrors *gr1 = new TGraphErrors(datain,"%lg %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 %*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("ALP");
   c01->Modified();
   c01->Update();
   mg->GetHistogram()->SetTitle("Global title");
   //mg->SetTitle("Graph Title");
   mg->GetXaxis()->SetTitle("x");
   mg->GetYaxis()->SetTitle("y");
   mg->GetYaxis()->SetTitleOffset(offy);
   mg->GetXaxis()->SetTitleOffset(offx);
   mg->GetXaxis()->SetTitleSize(XTitleSize);
   mg->GetYaxis()->SetTitleSize(YTitleSize);
  /* mg->GetYaxis()->SetLabelSize(YLabelSize);
  mg->GetXaxis()->SetLabelSize(XLabelSize);*/
   c01->Modified();
   c01->Update();
   TLegend* leg = new TLegend(0.15, 0.75, .2, .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();
   c01->cd();    
   c01->Update();
   TPad *pad2 = new TPad("pad2", "pad2", 0.0, 0.0, 1., 0.5);
   pad2->SetTopMargin(0.01);
   pad2->SetBottomMargin(1);
   pad2->SetGridx(); // vertical grid
   pad2->Draw();
   pad2->cd();       // pad2 becomes the current pad
   TGraphErrors *ratio = new TGraphErrors(datain,"%lg %*lg %*lg %lg");
   ratio->SetMarkerColor(kGreen+3);
   ratio->SetLineColor(kGreen+3);
   ratio->SetLineWidth(2);
   ratio->SetMarkerSize(2);
   ratio->SetMarkerStyle(29);
   ratio->Draw("ALP");
    ratio->SetTitle("");
   ratio->GetXaxis()->SetTitle("x");
   ratio->GetYaxis()->SetTitle("ratio");
   ratio->GetYaxis()->SetTitleOffset(offy);
   ratio->GetXaxis()->SetTitleOffset(offx);
   ratio->GetXaxis()->SetTitleSize(XTitleSize);
   ratio->GetYaxis()->SetTitleSize(YTitleSize);
  // ratio->GetYaxis()->SetLabelSize(YLabelSize);
   //ratio->GetXaxis()->SetLabelSize(XLabelSize);
   c01->Modified();
   c01->Update();
   TLegend* leg2 = new TLegend(0.15, 0.75, .2, .85);
   leg2->SetHeader("Legend");
   leg2->SetNColumns(1);
   leg2->AddEntry(ratio, "Difference", "ALP");
   leg2->Draw();
   gPad->Update();
    gPad->Update();
  // gPad->Update();
   c01->Print(dataout);

}