void plot_ped_sigma(void)
{
// 
// plot the contribution to the pedestal width from noise hits in the Bcal. Data from gen_bal_pulse.C
//

#include <TRandom.h>

gROOT->Reset();
//TTree *Bfield = (TTree *) gROOT->FindObject("Bfield");
gStyle->SetPalette(1,0);
gStyle->SetOptStat(kTRUE);
// gStyle->SetOptFit(kTRUE);
// gStyle->SetOptFit(1111);
gStyle->SetOptStat(111111);
gStyle->SetPadRightMargin(0.15);
gStyle->SetPadLeftMargin(0.15);
gStyle->SetPadBottomMargin(0.15);
gStyle->SetFillColor(0);
//

   char string[256];
   char filename[80];
   Int_t k,j,jj;
 

   // input data

  #define npts 7;

  Double_t mean[npts]={2,5,10,15,20,30,40};            // mean number of hits per 100 ns
  Double_t sig_est[npts]={0.08,0.2,0.4,0.6,0.8,1.2,1.6};          // estimated assuming Poisson distribution
  Double_t sig_nosmear[npts]={0.27,0.44,0.63,0.77,0.88,1.1,1.3};     // MC without pulse smearing, should approximate Poisson
  Double_t sig_smear[npts]={0.023,0.037,0.054,0.066,0.076,0.092,0.108};   // MC with pulse smearing, should average baseline

  TGraph *gest = new TGraph(npts,mean,sig_est);
  TGraph *gnosmear = new TGraph(npts,mean,sig_nosmear);
  TGraph *gsmear= new TGraph(npts,mean,sig_smear);
   

   TCanvas *c1 = new TCanvas("c1","c1 plot_ped_sigma",200,10,700,700);
   c1->SetBorderMode(0);
   c1->SetFillColor(0);
   // c1->SetGridx();
   // c1->SetGridy();
   // c1->SetLogy();

   /*c1->Divide(2,2);
   c1->cd(1);
   c1_1->SetBorderMode(0);
   c1_1->SetFillColor(0);*/


   TLegend *leg = new TLegend(0.2,0.75,0.55,0.9);
   gest->SetTitle("");
   // gest->GetYaxis()->SetRangeUser(0,100);   
   gest->GetXaxis()->SetTitleSize(0.04);
   gest->GetYaxis()->SetTitleSize(0.04);
   gest->GetYaxis()->SetTitleOffset(1.5);
   gest->GetXaxis()->SetTitle("Average Number of Hits in 100 ns");
   gest->GetYaxis()->SetTitle("Contribution to Ped Width (counts)");
   gest->GetXaxis()->SetNdivisions(505);
   gest->SetMarkerStyle(20);
   gest->SetMarkerColor(1);
   gest->Draw("Ap");
   leg->AddEntry(gest,"Stat Estimate","p");

   gnosmear->SetMarkerStyle(20);
   gnosmear->SetMarkerColor(4);
   gnosmear->Draw("samep");
   leg->AddEntry(gnosmear,"MC Without Smearing","p");

   gsmear->SetMarkerStyle(20);
   gsmear->SetMarkerColor(2);
   gsmear->Draw("samep");
   leg->AddEntry(gsmear,"MC Using Pulse Parm","p");

   leg->Draw();

   TLine *line = new TLine(0,1.3,44,1.3);
    line->SetLineWidth(2);
    line->SetLineColor(2);
    line->Draw();

    TLatex *text = new TLatex(4,1.23,"FCAL Ped Width");
    text->SetTextSize(0.03);
    text->Draw();
  
   sprintf(filename,"plot_ped_sigma.pdf");
   c1->SaveAs(filename);
   sprintf(filename,"plot_ped_sigma.png");
   c1->SaveAs(filename);

}