void size_studies(void)
{
//
// plot studies of acceptance as a function of light guide dimensions to optimize final production guide dimensions. 
// ES June 3, 2011
//

// #include <TMath.h>
#include <TRandom.h>

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

   char string[256];
   char filename[80];
   Int_t j,jj;
   
   #define npts 3;
   #define mpts 9;
   #define xpts 5;
   #define max 201;

   // input data set first point (actually -100) to 100 so that it is not plotted.
   // use offset on x-axis to make data visible and give negative y-values for reference (not plotted)

   Double_t dummyx[npts]={-1,0,5};
   Double_t dummyy[npts]={-1,-1,-1};

   // Computed light guide acceptances using geant3
   // To keep fixed lengths, use negative values for unmeasured parameters.

   Double_t acc_factor[mpts]={1.5*1.2,1.3*1.2,1.2*1.2,1.1*1.2,1.05*1.2,1.0*1.2,0.95*1.2,0.9*1.2,0.8*1.2};
   Double_t acc_g1[mpts]=       {   0.473,   0.637,     0.73,    0.748,      0.721,    0.671,      0.603,    0.541,  0.420};
   Double_t acc_g2[mpts]=       {         -1,          -1,         -1,    0.723,           -1,           -1,            -1,          -1,        -1};
   Double_t acc_g3[mpts]=       {         -1,          -1,         -1,    0.701,           -1,           -1,            -1,          -1,        -1};
   Double_t acc_g4[mpts]=       {         -1,          -1,   0.683,    0.683,     0.653,    0.612,            -1,          -1,        -1};
   Double_t acc_g5[mpts]=       {         -1,          -1,         -1,    0.662,           -1,            -1,            -1,          -1,        -1};
   Double_t acc_g6[mpts]=       {         -1,   0.494,    0.647,    0.643,    0.620,      0.579,            -1,          -1,        -1};
   Double_t acc_g7[mpts]=       {         -1,          -1,         -1,    0.516,           -1,           -1,            -1,          -1,        -1};
   Double_t acc_g8[mpts]=       {         -1,          -1,         -1,    0.503,           -1,           -1,            -1,          -1,        -1};
   Double_t acc_g9[mpts]=       {         -1,          -1,         -1,    0.488,           -1,           -1,            -1,          -1,        -1};
   Double_t acc_g10[mpts]=     {         -1,   0.492,     0.49,      0.477,         -1,      0.477,            -1,          -1,        -1};

   //
   TCanvas *c1 = new TCanvas("c1","c1 size_studies",200,10,700,700);

   c1->SetGridx();
   c1->SetGridy();
   c1->SetBorderMode(0);
   c1->SetFillColor(0);
   // c1->SetLogx();
   // c1->SetLogy();


   Double_t xmin=1;
   Double_t xmax=2;
   // Double_t xmin=0.1;
   // Double_t xmax=0.5;
   Double_t ymin=0;
   Double_t ymax=1.0;

   // dummy to draw axes

   TGraph *dummy = new TGraph (npts,dummyx,dummyy);
   TLegend *leg = new TLegend(0.7,0.5,0.85,0.9);

   dummy->SetMarkerColor(1);
   dummy->SetMarkerStyle(21);
   dummy->SetTitle("");
   dummy->GetXaxis()->SetRangeUser(xmin,xmax);
   dummy->GetYaxis()->SetRangeUser(ymin,ymax);
   dummy->GetXaxis()->SetTitleSize(0.04);
   dummy->GetYaxis()->SetTitleSize(0.04);
   dummy->GetYaxis()->SetTitleOffset(1.5);
   dummy->GetXaxis()->SetTitle("Height (cm)");
   dummy->GetYaxis()->SetTitle("Acceptance");
   dummy->Draw("Ap");
   // dummy->GetXaxis()->SetNdivisions(505);

  // plot data

   TGraph *ag1 = new TGraph (mpts,acc_factor,acc_g1);
   ag1->SetMarkerColor(2);
   ag1->SetMarkerStyle(20);
   ag1->Draw("Samep");
   sprintf (string,"Guide 1\n");
   leg->AddEntry(ag1,string,"p");

   TGraph *ag2 = new TGraph (mpts,acc_factor,acc_g2);
   ag2->SetMarkerColor(1);
   ag2->SetMarkerStyle(21);
   ag2->Draw("Samep");
   sprintf (string,"Guide 2\n");
   leg->AddEntry(ag2,string,"p");

   TGraph *ag3 = new TGraph (mpts,acc_factor,acc_g3);
   ag3->SetMarkerColor(3);
   ag3->SetMarkerStyle(22);
   ag3->Draw("Samep");
   sprintf (string,"Guide 3\n");
   leg->AddEntry(ag3,string,"p");

   TGraph *ag4 = new TGraph (mpts,acc_factor,acc_g4);
   ag4->SetMarkerColor(4);
   ag4->SetMarkerStyle(23);
   ag4->Draw("Samep");
   sprintf (string,"Guide 4\n");
   leg->AddEntry(ag4,string,"p");

   TGraph *ag5 = new TGraph (mpts,acc_factor,acc_g5);
   ag5->SetMarkerColor(2);
   ag5->SetMarkerStyle(24);
   ag5->Draw("Samep");
   sprintf (string,"Guide 5\n");
   leg->AddEntry(ag5,string,"p");

   TGraph *ag6 = new TGraph (mpts,acc_factor,acc_g6);
   ag6->SetMarkerColor(1);
   ag6->SetMarkerStyle(25);
   ag6->Draw("Samep");
   sprintf (string,"Guide 6\n");
   leg->AddEntry(ag6,string,"p");

   TGraph *ag7 = new TGraph (mpts,acc_factor,acc_g7);
   ag7->SetMarkerColor(3);
   ag7->SetMarkerStyle(26);
   ag7->Draw("Samep");
   sprintf (string,"Guide 7\n");
   leg->AddEntry(ag7,string,"p");

   TGraph *ag8 = new TGraph (mpts,acc_factor,acc_g8);
   ag8->SetMarkerColor(4);
   ag8->SetMarkerStyle(27);
   ag8->Draw("Samep");
   sprintf (string,"Guide 8\n");
   leg->AddEntry(ag8,string,"p");

   TGraph *ag9 = new TGraph (mpts,acc_factor,acc_g9);
   ag9->SetMarkerColor(2);
   ag9->SetMarkerStyle(28);
   ag9->Draw("Samep");
   sprintf (string,"Guide 9\n");
   leg->AddEntry(ag9,string,"p");

   TGraph *ag10 = new TGraph (mpts,acc_factor,acc_g10);
   ag10->SetMarkerColor(1);
   ag10->SetMarkerStyle(29);
   ag10->Draw("Samep");
   sprintf (string,"Guide 10\n");
   leg->AddEntry(ag10,string,"p");

   leg->Draw();

   sprintf (string,"Title\n");
   t1 = new TLatex(0.6,0.88,string);
   t1->SetTextColor(1);
   t1->SetNDC();
   t1->SetTextSize(0.025);
   // t1->Draw(); 

   TLine *line = new TLine (1.27,ymin,1.27,ymax);
   // line->SetLineStyle(2);
   line->SetLineColor(2);
   line->SetLineWidth(2);
   line->Draw();


   sprintf(filename,"size_studies_c1.eps");
   c1->SaveAs(filename);
   sprintf(filename,"size_studies_c1.png");
   c1->SaveAs(filename);
}