#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> // for "exit"

/*const char *labelsgamma[] = {"30.53 GeV", "69.34 GeV", "138.70 GeV", "260.98 GeV", "453.25 GeV", "765.59 GeV"};

void drawlabels(TGraph *g = 0,
                const char *labels[] = 0)
{
  if ((!g) || (!labels) || (!gPad)) return; // just a precaution
  
  for (Int_t i = 0; i < g->GetN(); i++) {
    Double_t x, y;
    g->GetPoint(i, x, y);
    if (gPad->GetLogx()) x *= 1.25; else x+= 0.0;
    if (gPad->GetLogy()) y *= 1.25; else y+= 0.0;
    TLatex *l = new TLatex(x, y, labels[i]);
    l->SetTextSize(0.025);
    l->SetTextFont(42);
    l->SetTextAlign(21);
    l->SetTextColor(g->GetMarkerColor());
    l->Draw();
  }
}*/

void corona() {
	gStyle->SetOptFit();
	const char *datain = "C:/corona.txt";
	const char *dataout = "C:/root_v6.20.00/corona.pdf";

	TCanvas *c01 = new TCanvas("c01","multigraph",1280,1024);
	float offx=1.3;
	float offy=1.7;
	float margr=0.08;
	float w=3;
	float margl=0.12;
	gPad->SetLeftMargin(margl);
	gPad->SetRightMargin(margr);
	
	TGraphErrors *gamma = new TGraphErrors(datain,"%lg %lg");
	gamma->SetMarkerColor(kBlue);
	gamma->SetLineColor(kBlue);
	gamma->SetMarkerStyle(23);
	gamma->SetLineWidth(10);

	TF1 *fitspettro = new TF1("fitspettro", "gaus");
	gamma->Fit("fitspettro");
	fitspettro->SetRange(0.,100);
	fitspettro->Draw();
	gamma->Draw("L");
	
	fitspettro->SetTitle("Covid-19 cases");
	fitspettro->GetXaxis()->SetTitle("Day");
	fitspettro->GetYaxis()->SetTitle("Cases");
	fitspettro->GetYaxis()->SetTitleOffset(offy);
	fitspettro->GetXaxis()->SetTitleOffset(offx);
    
	TLegend* leg = new TLegend(0.15, 0.7, .25, .75);
	leg->SetHeader("Legend");
	leg->SetNColumns(1);
	leg->AddEntry(gamma, "Data", "l");
	leg->AddEntry(fitspettro, "Fit", "l");  
	leg->Draw(); 
	c01->Print(dataout);
}