class THistPainter: public TVirtualHistPainter

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   // create/fill draw h1
   gStyle->SetOptStat(kFALSE);
   TH1F *h1 = new TH1F("h1","Superimposing two histograms with different scales",100,-3,3);
   Int_t i;
   for (i=0;i<10000;i++) h1->Fill(gRandom->Gaus(0,1));
   h1->Draw();
   c1->Update();

   // create hint1 filled with the bins integral of h1
   TH1F *hint1 = new TH1F("hint1","h1 bins integral",100,-3,3);
   Float_t sum = 0;
   for (i=1;i<=100;i++) {
      sum += h1->GetBinContent(i);
      hint1->SetBinContent(i,sum);
   }

   // scale hint1 to the pad coordinates
   Float_t rightmax = 1.1*hint1->GetMaximum();
   Float_t scale = gPad->GetUymax()/rightmax;
   hint1->SetLineColor(kRed);
   hint1->Scale(scale);
   hint1->Draw("same");

   // draw an axis on the right side
   TGaxis *axis = new TGaxis(gPad->GetUxmax(),gPad->GetUymin(),
   gPad->GetUxmax(), gPad->GetUymax(),0,rightmax,510,"+L");
   axis->SetLineColor(kRed);
   axis->SetTextColor(kRed);
   axis->Draw();
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH1F *he = new TH1F("he","Distribution drawn with error bars (option E1)  ",100,-3,3);
   Int_t i;
   for (i=0;i<10000;i++) he->Fill(gRandom->Gaus(0,1));
   gStyle->SetEndErrorSize(3);
   gStyle->SetErrorX(1.);
   he->SetMarkerStyle(20);
   he->Draw("E1");
   return c1;
}

{
   TCanvas *ce4 = new TCanvas("ce4","ce4",600,400);
   ce4->Divide(2,1);
   TH1F *he4 = new TH1F("he4","Distribution drawn with option E4",100,-3,3);
   Int_t i;
   for (i=0;i<10000;i++) he4->Fill(gRandom->Gaus(0,1));
   he4->SetFillColor(kRed);
   he4->GetXaxis()->SetRange(40,48);
   ce4->cd(1);
   he4->Draw("E4");
   ce4->cd(2);
   TH1F *he3 = (TH1F*)he4->DrawClone("E3");
   he3->SetTitle("Distribution drawn option E3");
   return ce4;
}

{
   TCanvas *c2e = new TCanvas("c2e","c2e",600,400);
   TH2F *h2e = new TH2F("h2e","TH2 drawn with option E",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      h2e->Fill(px,5*py);
   }
   h2e->Draw("E");
   return c2e;
}

{
   int i;
   const Int_t nx = 8;
   char *os_X[nx]   = {"8","32","128","512","2048","8192","32768","131072"};
   float d_35_0[nx] = {0.75, -3.30, -0.92, 0.10, 0.08, -1.69, -1.29, -2.37};
   float d_35_1[nx] = {1.01, -3.02, -0.65, 0.37, 0.34, -1.42, -1.02, -2.10};

   TCanvas *cb = new TCanvas("cb","cb",600,400);
   cb->SetGrid();

   gStyle->SetHistMinimumZero();

   TH1F *h1b = new TH1F("h1b","Option B example",nx,0,nx);
   h1b->SetFillColor(4);
   h1b->SetBarWidth(0.4);
   h1b->SetBarOffset(0.1);
   h1b->SetStats(0);
   h1b->SetMinimum(-5);
   h1b->SetMaximum(5);

   for (i=1; i<=nx; i++) {
      h1b->Fill(os_X[i-1], d_35_0[i-1]);
      h1b->GetXaxis()->SetBinLabel(i,os_X[i-1]);
   }

   h1b->Draw("b");

   TH1F *h2b = new TH1F("h2b","h2b",nx,0,nx);
   h2b->SetFillColor(38);
   h2b->SetBarWidth(0.4);
   h2b->SetBarOffset(0.5);
   h2b->SetStats(0);
   for (i=1;i<=nx;i++) h2b->Fill(os_X[i-1], d_35_1[i-1]);

   h2b->Draw("b same");

   return cb;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hscat = new TH2F("hscat","Option SCATter example (default for 2D histograms)  ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hscat->Fill(px,5*py);
      hscat->Fill(3+0.5*px,2*py-10.);
   }
   hscat->Draw("scat=0.5");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *harr = new TH2F("harr","Option ARRow example",20,-4,4,20,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      harr->Fill(px,5*py);
      harr->Fill(3+0.5*px,2*py-10.,0.1);
   }
   harr->Draw("ARR");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   hbox  = new TH2F("hbox","Option BOX example",3,0,3,3,0,3);
   hbox->SetFillColor(42);
   hbox->Fill(0.5, 0.5,  1.);
   hbox->Fill(0.5, 1.5,  4.);
   hbox->Fill(0.5, 2.5,  3.);
   hbox->Fill(1.5, 0.5,  2.);
   hbox->Fill(1.5, 1.5, 12.);
   hbox->Fill(1.5, 2.5, -6.);
   hbox->Fill(2.5, 0.5, -4.);
   hbox->Fill(2.5, 1.5,  6.);
   hbox->Fill(2.5, 2.5,  0.5);
   hbox->Draw("BOX");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   hbox1  = new TH2F("hbox1","Option BOX1 example",3,0,3,3,0,3);
   hbox1->SetFillColor(42);
   hbox1->Fill(0.5, 0.5,  1.);
   hbox1->Fill(0.5, 1.5,  4.);
   hbox1->Fill(0.5, 2.5,  3.);
   hbox1->Fill(1.5, 0.5,  2.);
   hbox1->Fill(1.5, 1.5, 12.);
   hbox1->Fill(1.5, 2.5, -6.);
   hbox1->Fill(2.5, 0.5, -4.);
   hbox1->Fill(2.5, 1.5,  6.);
   hbox1->Fill(2.5, 2.5,  0.5);
   hbox1->Draw("BOX1");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hb1 = new TH2F("hb1","Example of BOX plots with option SAME ",40,-3,3,40,-3,3);
   TH2F *hb2 = new TH2F("hb2","hb2",40,-3,3,40,-3,3);
   TH2F *hb3 = new TH2F("hb3","hb3",40,-3,3,40,-3,3);
   TH2F *hb4 = new TH2F("hb4","hb4",40,-3,3,40,-3,3);
   for (Int_t i=0;i<1000;i++) {
      double x,y;
      gRandom->Rannor(x,y);
      if (x>0 && y>0) hb1->Fill(x,y,4);
      if (x<0 && y<0) hb2->Fill(x,y,3);
      if (x>0 && y<0) hb3->Fill(x,y,2);
      if (x<0 && y>0) hb4->Fill(x,y,1);
   }
   hb1->SetFillColor(1);
   hb2->SetFillColor(2);
   hb3->SetFillColor(3);
   hb4->SetFillColor(4);
   hb1->Draw("box");
   hb2->Draw("box same");
   hb3->Draw("box same");
   hb4->Draw("box same");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcol1 = new TH2F("hcol1","Option COLor example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcol1->Fill(px,5*py);
   }
   gStyle->SetPalette(1);
   hcol1->Draw("COLZ");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcol2 = new TH2F("hcol2","Option COLor example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcol2->Fill(px,5*py);
   }
   hcol2->Fill(0.,0.,-200.);
   gStyle->SetPalette(1);
   hcol2->Draw("COLZ");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcandle = new TH2F("hcandle","Option CANDLE example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcandle->Fill(px,5*py);
   }
   hcandle->SetMarkerSize(0.5);
   hcandle->Draw("CANDLE");
   return c1;
}

{
    TCanvas *c1 = new TCanvas("c1","c1",600,400);
    Int_t nx(6), ny(40);
    Double_t xmin(0.0), xmax(+6.0), ymin(0.0), ymax(+4.0);
    TH2F* hviolin = new TH2F("hviolin", "Option VIOLIN example", nx, xmin, xmax, ny, ymin, ymax);
    TF1 f1("f1", "gaus", +0,0 +4.0);
    Double_t x,y;
    for (Int_t iBin=1; iBin<hviolin->GetNbinsX(); ++iBin) {
        Double_t xc = hviolin->GetXaxis()->GetBinCenter(iBin);
        f1.SetParameters(1, 2.0+TMath::Sin(1.0+xc), 0.2+0.1*(xc-xmin)/xmax);
        for(Int_t i=0; i<10000; ++i){
            x = xc;
            y = f1.GetRandom();
            hviolin->Fill(x, y);
        }
    }
    hviolin->SetFillColor(kGray);
    hviolin->SetMarkerStyle(20);
    hviolin->SetMarkerSize(0.5);
    hviolin->Draw("VIOLIN");
    c1->Update();
    return c1;
}

{
   TCanvas *c01 = new TCanvas("c01","c01",700,400);
   c01->Divide(2,1);
   TH1F *htext1 = new TH1F("htext1","Option TEXT on 1D histograms ",10,-4,4);
   TH2F *htext2 = new TH2F("htext2","Option TEXT on 2D histograms ",10,-4,4,10,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
        htext1->Fill(px,0.1);
      htext2->Fill(px,5*py,0.1);
   }
   gStyle->SetPaintTextFormat("4.1f m");
   htext2->SetMarkerSize(1.8);
   c01->cd(1);
   htext2->Draw("TEXT45");
   c01->cd(2);
   htext1->Draw();
   htext1->Draw("TEXT0 SAME");
   return c01;
}

{
   TCanvas *c02 = new TCanvas("c02","c02",700,400);
   c02->Divide(2,1);
   gStyle->SetPaintTextFormat("g");

   TProfile *profile = new TProfile("profile","profile",10,0,10);
   profile->SetMarkerSize(2.2);
   profile->Fill(0.5,1);
   profile->Fill(1.5,2);
   profile->Fill(2.5,3);
   profile->Fill(3.5,4);
   profile->Fill(4.5,5);
   profile->Fill(5.5,5);
   profile->Fill(6.5,4);
   profile->Fill(7.5,3);
   profile->Fill(8.5,2);
   profile->Fill(9.5,1);
   c02->cd(1); profile->Draw("HIST TEXT0");
   c02->cd(2); profile->Draw("HIST TEXT0E");

   return c02;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcontz = new TH2F("hcontz","Option CONTZ example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcontz->Fill(px-1,5*py);
      hcontz->Fill(2+0.5*px,2*py-10.,0.1);
   }
   gStyle->SetPalette(1);
   hcontz->Draw("CONTZ");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcont1 = new TH2F("hcont1","Option CONT1Z example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcont1->Fill(px-1,5*py);
      hcont1->Fill(2+0.5*px,2*py-10.,0.1);
   }
   gStyle->SetPalette(1);
   hcont1->Draw("CONT1Z");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcont2 = new TH2F("hcont2","Option CONT2 example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcont2->Fill(px-1,5*py);
      hcont2->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hcont2->Draw("CONT2");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcont3 = new TH2F("hcont3","Option CONT3 example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcont3->Fill(px-1,5*py);
      hcont3->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hcont3->Draw("CONT3");
   return c1;
}

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *hcont4 = new TH2F("hcont4","Option CONT4Z example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcont4->Fill(px-1,5*py);
      hcont4->Fill(2+0.5*px,2*py-10.,0.1);
   }
   gStyle->SetPalette(1);
   hcont4->Draw("CONT4Z");
   return c1;
}

// Getting Contours From TH2D
// Author: Josh de Bever
//         CSI Medical Physics Group
//         The University of Western Ontario
//         London, Ontario, Canada
//   Date: Oct. 22, 2004
//   Modified by O.Couet (Nov. 26, 2004)

TCanvas *ContourList(){

   const Double_t PI = TMath::Pi();

   TCanvas* c = new TCanvas("c","Contour List",0,0,600,600);
   c->SetRightMargin(0.15);
   c->SetTopMargin(0.15);

   Int_t i, j, TotalConts;

   Int_t nZsamples   = 80;
   Int_t nPhiSamples = 80;

   Double_t HofZwavelength = 4.0;       // 4 meters
   Double_t dZ             =  HofZwavelength/(Double_t)(nZsamples - 1);
   Double_t dPhi           = 2*PI/(Double_t)(nPhiSamples - 1);

   TArrayD z(nZsamples);
   TArrayD HofZ(nZsamples);
   TArrayD phi(nPhiSamples);
   TArrayD FofPhi(nPhiSamples);

   // Discretized Z and Phi Values
   for ( i = 0; i < nZsamples; i++) {
      z[i] = (i)*dZ - HofZwavelength/2.0;
      HofZ[i] = SawTooth(z[i], HofZwavelength);
   }

   for(Int_t i=0; i < nPhiSamples; i++){
      phi[i] = (i)*dPhi;
      FofPhi[i] = sin(phi[i]);
   }

   // Create Histogram
   TH2D *HistStreamFn = new TH2D("HstreamFn",
   "#splitline{Histogram with negative and positive contents. Six contours are defined.}{It is plotted with options CONT LIST to retrieve the contours points in TGraphs}",
   nZsamples, z[0], z[nZsamples-1], nPhiSamples, phi[0], phi[nPhiSamples-1]);

   // Load Histogram Data
   for (Int_t i = 0; i < nZsamples; i++) {
      for(Int_t j = 0; j < nPhiSamples; j++){
         HistStreamFn->SetBinContent(i,j, HofZ[i]*FofPhi[j]);
      }
   }

   gStyle->SetPalette(1);
   gStyle->SetOptStat(0);
   gStyle->SetTitleW(0.99);
   gStyle->SetTitleH(0.08);

   Double_t contours[6];
   contours[0] = -0.7;
   contours[1] = -0.5;
   contours[2] = -0.1;
   contours[3] =  0.1;
   contours[4] =  0.4;
   contours[5] =  0.8;

   HistStreamFn->SetContour(6, contours);

   // Draw contours as filled regions, and Save points
   HistStreamFn->Draw("CONT Z LIST");
   c->Update(); // Needed to force the plotting and retrieve the contours in TGraphs

   // Get Contours
   TObjArray *conts = (TObjArray*)gROOT->GetListOfSpecials()->FindObject("contours");
   TList* contLevel = NULL;
   TGraph* curv     = NULL;
   TGraph* gc       = NULL;

   Int_t nGraphs    = 0;
   Int_t TotalConts = 0;

   if (conts == NULL){
      printf("*** No Contours Were Extracted!\n");
      TotalConts = 0;
      return;
   } else {
      TotalConts = conts->GetSize();
   }

   printf("TotalConts = %d\n", TotalConts);

   for(i = 0; i < TotalConts; i++){
      contLevel = (TList*)conts->At(i);
      printf("Contour %d has %d Graphs\n", i, contLevel->GetSize());
      nGraphs += contLevel->GetSize();
   }

   nGraphs = 0;

   TCanvas* c1 = new TCanvas("c1","Contour List",610,0,600,600);
   c1->SetTopMargin(0.15);
   TH2F *hr = new TH2F("hr",
   "#splitline{Negative contours are returned first (highest to lowest). Positive contours are returned from}{lowest to highest. On this plot Negative contours are drawn in red and positive contours in blue.}",
   2, -2, 2, 2, 0, 6.5);

   hr->Draw();
   Double_t x0, y0, z0;
   TLatex l;
   l.SetTextSize(0.03);
   char val[20];

   for(i = 0; i < TotalConts; i++){
      contLevel = (TList*)conts->At(i);
      if (i<3) z0 = contours[2-i];
      else     z0 = contours[i];
      printf("Z-Level Passed in as:  Z = %f\n", z0);

      // Get first graph from list on curves on this level
      curv = (TGraph*)contLevel->First();
      for(j = 0; j < contLevel->GetSize(); j++){
         curv->GetPoint(0, x0, y0);
         if (z0<0) curv->SetLineColor(kRed);
         if (z0>0) curv->SetLineColor(kBlue);
         nGraphs ++;
         printf("\tGraph: %d  -- %d Elements\n", nGraphs,curv->GetN());

         // Draw clones of the graphs to avoid deletions in case the 1st
         // pad is redrawn.
         gc = (TGraph*)curv->Clone();
         gc->Draw("C");

         sprintf(val,"%g",z0);
         l.DrawLatex(x0,y0,val);
         curv = (TGraph*)contLevel->After(curv); // Get Next graph
      }
   }
   c1->Update();
   printf("\n\n\tExtracted %d Contours and %d Graphs \n", TotalConts, nGraphs );
   gStyle->SetTitleW(0.);
   gStyle->SetTitleH(0.);
   return c1;
}


Double_t SawTooth(Double_t x, Double_t WaveLen){

// This function is specific to a sawtooth function with period
// WaveLen, symmetric about x = 0, and with amplitude = 1. Each segment
// is 1/4 of the wavelength.
//
//           |
//      /\   |
//     /  \  |
//    /    \ |
//   /      \
//  /--------\--------/------------
//           |\      /
//           | \    /
//           |  \  /
//           |   \/
//

   Double_t y;
   if ( (x < -WaveLen/2) || (x > WaveLen/2)) y = -99999999; // Error X out of bounds
   if (x <= -WaveLen/4) {
      y = x + 2.0;
   } else if ((x > -WaveLen/4) && (x <= WaveLen/4)) {
      y = -x ;
   } else if (( x > WaveLen/4) && (x <= WaveLen/2)) {
      y = x - 2.0;
   }
   return y;
}

{
  //this tutorial illustrate the special contour options
  //    "AITOFF"     : Draw a contour via an AITOFF projection
  //    "MERCATOR"   : Draw a contour via an Mercator projection
  //    "SINUSOIDAL" : Draw a contour via an Sinusoidal projection
  //    "PARABOLIC"  : Draw a contour via an Parabolic projection
  // 
  //Author: Olivier Couet (from an original macro sent by Ernst-Jan Buis)
    
   gStyle->SetPalette(1);
   gStyle->SetOptTitle(1);
   gStyle->SetOptStat(0);

   TCanvas *c1 = new TCanvas("c1","earth_projections",700,700);
   c1->Divide(2,2);

   TH2F *ha = new TH2F("ha","Aitoff",    180, -180, 180, 179, -89.5, 89.5);
   TH2F *hm = new TH2F("hm","Mercator",  180, -180, 180, 161, -80.5, 80.5);
   TH2F *hs = new TH2F("hs","Sinusoidal",180, -180, 180, 181, -90.5, 90.5);
   TH2F *hp = new TH2F("hp","Parabolic", 180, -180, 180, 181, -90.5, 90.5);

   TString dat = gSystem->UnixPathName(gInterpreter->GetCurrentMacroName());
   dat.ReplaceAll("C","dat");
   dat.ReplaceAll("/./","/");

   ifstream in;
   in.open(dat.Data());
   Float_t x,y;
   while (1) {
     in >> x >> y;
     if (!in.good()) break;
     ha->Fill(x,y, 1);
     hm->Fill(x,y, 1);
     hs->Fill(x,y, 1);
     hp->Fill(x,y, 1);
   }
   in.close();

   c1->cd(1); ha->Draw("aitoff");
   c1->cd(2); hm->Draw("mercator");
   c1->cd(3); hs->Draw("sinusoidal");
   c1->cd(4); hp->Draw("parabolic");

   return c1;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hlego = new TH2F("hlego","Option LEGO example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hlego->Fill(px-1,5*py);
      hlego->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hlego->Draw("LEGO");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hlego1 = new TH2F("hlego1","Option LEGO1 example (with option 0)  ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hlego1->Fill(px-1,5*py);
      hlego1->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hlego1->SetFillColor(kYellow);
   hlego1->Draw("LEGO1 0");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hlego3 = new TH2F("hlego3","Option LEGO3 example",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hlego3->Fill(px-1,5*py);
      hlego3->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hlego3->SetFillColor(kRed);
   hlego3->Draw("LEGO3");
   return c2;
 }

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hlego2 = new TH2F("hlego2","Option LEGO2Z example ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hlego2->Fill(px-1,5*py);
      hlego2->Fill(2+0.5*px,2*py-10.,0.1);
   }
   gStyle->SetPalette(1);
   hlego2->Draw("LEGO2Z");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf = new TH2F("hsurf","Option SURF example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf->Fill(px-1,5*py);
      hsurf->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf->Draw("SURF");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf1 = new TH2F("hsurf1","Option SURF1 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf1->Fill(px-1,5*py);
      hsurf1->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf1->Draw("SURF1");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf2 = new TH2F("hsurf2","Option SURF2 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf2->Fill(px-1,5*py);
      hsurf2->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf2->Draw("SURF2");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf3 = new TH2F("hsurf3","Option SURF3 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf3->Fill(px-1,5*py);
      hsurf3->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf3->Draw("SURF3");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf4 = new TH2F("hsurf4","Option SURF4 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf4->Fill(px-1,5*py);
      hsurf4->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf4->SetFillColor(kOrange);
   hsurf4->Draw("SURF4");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf5 = new TH2F("hsurf4","Option SURF5 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf5->Fill(px-1,5*py);
      hsurf5->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf5->SetFillColor(kOrange);
   hsurf5->Draw("SURF5 CYL");
   return c2;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TH2F *hsurf7 = new TH2F("hsurf3","Option SURF7 example ",30,-4,4,30,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hsurf7->Fill(px-1,5*py);
      hsurf7->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hsurf7->Draw("SURF7");
   return c2;
}

{
   TCanvas *c20=new TCanvas("c20","c20",600,400);
   int NBins = 50;
   double d = 2;
   TH2F* hsc = new TH2F("hsc", "Surface and contour with option SAME ", NBins, -d, d, NBins, -d, d);
   for (int bx = 1;  bx <= NBins; ++bx) {
      for (int by = 1;  by <= NBins; ++by) {
         double x = hsc->GetXaxis()->GetBinCenter(bx);
         double y = hsc->GetYaxis()->GetBinCenter(by);
         hsc->SetBinContent(bx, by, exp(-x*x)*exp(-y*y));
      }
   }
   gStyle->SetPalette(1);
   hsc->Draw("surf2");
   hsc->Draw("CONT1 SAME");
   return c20;
}

{
   TCanvas *c3 = new TCanvas("c3","c3",600,400);
   c3->Divide(2,2);
   TH2F *hlcc = new TH2F("hlcc","Cylindrical coordinates",20,-4,4,20,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hlcc->Fill(px-1,5*py);
      hlcc->Fill(2+0.5*px,2*py-10.,0.1);
   }
   hlcc->SetFillColor(kYellow);
   c3->cd(1); hlcc->Draw("LEGO1 CYL");
   c3->cd(2); TH2F *hlpc = (TH2F*) hlcc->DrawClone("LEGO1 POL");
   hlpc->SetTitle("Polar coordinates");
   c3->cd(3); TH2F *hlsc = (TH2F*) hlcc->DrawClone("LEGO1 SPH");
   hlsc->SetTitle("Spherical coordinates");
   c3->cd(4); TH2F *hlprpc = (TH2F*) hlcc->DrawClone("LEGO1 PSR");
   hlprpc->SetTitle("PseudoRapidity/Phi coordinates");
   return c3;
}

{
   TCanvas *c4 = new TCanvas("c4","c4",600,400);
   c4->Divide(2,2);
   TH2F *hscc = new TH2F("hscc","Cylindrical coordinates",20,-4,4,20,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hscc->Fill(px-1,5*py);
      hscc->Fill(2+0.5*px,2*py-10.,0.1);
   }
   gStyle->SetPalette(1);
   c4->cd(1); hscc->Draw("SURF1 CYL");
   c4->cd(2); TH2F *hspc = (TH2F*) hscc->DrawClone("SURF1 POL");
   hspc->SetTitle("Polar coordinates");
   c4->cd(3); TH2F *hssc = (TH2F*) hscc->DrawClone("SURF1 SPH");
   hssc->SetTitle("Spherical coordinates");
   c4->cd(4); TH2F *hsprpc = (TH2F*) hscc->DrawClone("SURF1 PSR");
   hsprpc->SetTitle("PseudoRapidity/Phi coordinates");
   return c4;
}

{
   TCanvas *c5 = new TCanvas("c5","c5",700,400);
   c5->Divide(2,1);
   gStyle->SetHistMinimumZero(1);
   TH1F *hz1 = new TH1F("hz1","Bar-chart drawn from 0",20,-3,3);
   TH2F *hz2 = new TH2F("hz2","Lego plot drawn from 0",20,-3,3,20,-3,3);
   Int_t i;
   Double_t x,y;
   hz1->SetFillColor(kBlue);
   hz2->SetFillColor(kBlue);
   for (i=0;i<10000;i++) {
      x = gRandom->Gaus(0,1);
      y = gRandom->Gaus(0,1);
      if (x>0) {
         hz1->Fill(x,1);
         hz2->Fill(x,y,1);
      } else {
         hz1->Fill(x,-1);
         hz2->Fill(x,y,-2);
      }
   }
   c5->cd(1); hz1->Draw("bar2");
   c5->cd(2); hz2->Draw("lego1");
   return c5;
}

{
   int i;
   const Int_t nx = 8;
   char *os_X[nx]   = {"8","32","128","512","2048","8192","32768","131072"};
   float d_35_0[nx] = {0.75, -3.30, -0.92, 0.10, 0.08, -1.69, -1.29, -2.37};
   float d_35_1[nx] = {1.01, -3.02, -0.65, 0.37, 0.34, -1.42, -1.02, -2.10};

   TCanvas *cbh = new TCanvas("cbh","cbh",400,600);
   cbh->SetGrid();

   gStyle->SetHistMinimumZero();

   TH1F *h1bh = new TH1F("h1bh","Option HBAR centered on 0",nx,0,nx);
   h1bh->SetFillColor(4);
   h1bh->SetBarWidth(0.4);
   h1bh->SetBarOffset(0.1);
   h1bh->SetStats(0);
   h1bh->SetMinimum(-5);
   h1bh->SetMaximum(5);

   for (i=1; i<=nx; i++) {
      h1bh->Fill(os_X[i-1], d_35_0[i-1]);
      h1bh->GetXaxis()->SetBinLabel(i,os_X[i-1]);
   }

   h1bh->Draw("hbar");

   TH1F *h2bh = new TH1F("h2bh","h2bh",nx,0,nx);
   h2bh->SetFillColor(38);
   h2bh->SetBarWidth(0.4);
   h2bh->SetBarOffset(0.5);
   h2bh->SetStats(0);
   for (i=1;i<=nx;i++) h2bh->Fill(os_X[i-1], d_35_1[i-1]);

   h2bh->Draw("hbar same");

   return cbh;
}

{
   TCanvas *ch2p1 = new TCanvas("ch2p1","ch2p1",600,400);
   TH2Poly *h2p = new TH2Poly();
   h2p->SetName("h2poly_name");
   h2p->SetTitle("h2poly_title");
   Double_t px1[] = {0, 5, 6};
   Double_t py1[] = {0, 0, 5};
   Double_t px2[] = {0, -1, -1, 0};
   Double_t py2[] = {0, 0, -1, 3};
   Double_t px3[] = {4, 3, 0, 1, 2.4};
   Double_t py3[] = {4, 3.7, 1, 3.7, 2.5};
   h2p->AddBin(3, px1, py1);
   h2p->AddBin(4, px2, py2);
   h2p->AddBin(5, px3, py3);
   h2p->Fill(0.1, 0.01, 3);
   h2p->Fill(-0.5, -0.5, 7);
   h2p->Fill(-0.7, -0.5, 1);
   h2p->Fill(1, 3, 1.5);
   Double_t fx[] = {0.1, -0.5, -0.7, 1};
   Double_t fy[] = {0.01, -0.5, -0.5, 3};
   Double_t fw[] = {3, 1, 1, 1.5};
   h2p->FillN(4, fx, fy, fw);
   gStyle->SetPalette(1);
   h2p->Draw("col");
   return ch2p1;
}

//This tutorial illustrates how to create an histogram with polygonal
//bins (TH2Poly). The bins are boxes.
//
//Author: Olivier Couet

{
   TCanvas *ch2p2 = new TCanvas("ch2p2","ch2p2",600,400);
   TH2Poly *h2p = new TH2Poly();
   h2p->SetName("Boxes");
   h2p->SetTitle("Boxes");
   gStyle->SetPalette(1);

   Int_t i,j;
   Int_t nx = 40;
   Int_t ny = 40;
   Double_t x1,y1,x2,y2;
   Double_t dx=0.2, dy=0.1;
   x1 = 0.;
   x2 = dx;

   for (i = 0; i<nx; i++) {
      y1 = 0.;
      y2 = dy;
      for (j = 0; j<ny; j++) {
         h2p->AddBin(x1, y1, x2, y2);
         y1 = y2;
         y2 = y2+y2*dy;
      }
      x1 = x2;
      x2 = x2+x2*dx;
   }

   TRandom ran;
   for (i = 0; i<300000; i++) {
      h2p->Fill(50*ran.Gaus(2.,1), ran.Gaus(2.,1));
   }

   h2p->Draw("COLZ");
   return ch2p2;
}

{
   TCanvas *ch2p2 = new TCanvas("ch2p2","ch2p2",600,400);

   Int_t i, bin;
   const Int_t nx = 48;
   const char *states [nx] = {
      "alabama",      "arizona",        "arkansas",       "california",
      "colorado",     "connecticut",    "delaware",       "florida",
      "georgia",      "idaho",          "illinois",       "indiana",
      "iowa",         "kansas",         "kentucky",       "louisiana",
      "maine",        "maryland",       "massachusetts",  "michigan",
      "minnesota",    "mississippi",    "missouri",       "montana",
      "nebraska",     "nevada",         "new_hampshire",  "new_jersey",
      "new_mexico",   "new_york",       "north_carolina", "north_dakota",
      "ohio",         "oklahoma",       "oregon",         "pennsylvania",
      "rhode_island", "south_carolina", "south_dakota",   "tennessee",
      "texas",        "utah",           "vermont",        "virginia",
      "washington",   "west_virginia",  "wisconsin",      "wyoming"
   };
   Double_t pop[nx] = {
    4708708, 6595778,  2889450, 36961664, 5024748,  3518288,  885122, 18537969,
    9829211, 1545801, 12910409,  6423113, 3007856,  2818747, 4314113,  4492076,
    1318301, 5699478,  6593587,  9969727, 5266214,  2951996, 5987580,   974989,
    1796619, 2643085,  1324575,  8707739, 2009671, 19541453, 9380884,   646844,
   11542645, 3687050,  3825657, 12604767, 1053209,  4561242,  812383,  6296254,
   24782302, 2784572,   621760,  7882590, 6664195,  1819777, 5654774,   544270
   };

   Double_t lon1 = -130;
   Double_t lon2 = -65;
   Double_t lat1 = 24;
   Double_t lat2 = 50;
   TH2Poly *p = new TH2Poly("USA","USA Population",lon1,lon2,lat1,lat2);

   TFile *f;
   f = TFile::Open("http://root.cern.ch/files/usa.root");

   TMultiGraph *mg;
   TKey *key;
   TIter nextkey(gDirectory->GetListOfKeys());
   while ((key = (TKey*)nextkey())) {
      TObject *obj = key->ReadObj();
      if (obj->InheritsFrom("TMultiGraph")) {
         mg = (TMultiGraph*)obj;
         bin = p->AddBin(mg);
      }
   }

   for (i=0; i<nx; i++) p->Fill(states[i], pop[i]);

   gStyle->SetOptStat(11);
   gStyle->SetPalette(1);
   p->Draw("COLZ L");
   return ch2p2;
}

#include "TF2.h"
#include "TH2.h"
#include "TCutG.h"
#include "TMath.h"
#include "TCanvas.h"
#include "TStyle.h"


//+ Fitting a 2-D histogram (a variant)
// This tutorial illustrates :
//  - how to create a 2-d function
//  - fill a 2-d histogram randomly from this function
//  - fit the histogram
//  - display the fitted function on top of the histogram (lego-plot)
//    using a surface plot in a sub-range of the histogram.
//
// This example can be executed via the interpreter or/and the compiler
//   root > .x fit2a.C
//   root > .x fit2a.C++
//Author: Rene Brun
         
Double_t g2(Double_t *x, Double_t *par) {
   Double_t r1 = Double_t((x[0]-par[1])/par[2]);
   Double_t r2 = Double_t((x[1]-par[3])/par[4]);
   return par[0]*TMath::Exp(-0.5*(r1*r1+r2*r2));
}   
Double_t fun2(Double_t *x, Double_t *par) {
   Double_t *p1 = &par[0];
   Double_t *p2 = &par[5];
   Double_t *p3 = &par[10];
   Double_t result = g2(x,p1) + g2(x,p2) + g2(x,p3);
   return result;
}

TCanvas *fit2a() {
   TCanvas *c = new TCanvas();
   gStyle->SetOptStat(kTRUE); 
   gStyle->SetPalette(1); 
   const Int_t npar = 15;
   Double_t f2params[npar] = {100,-3,3,-3,3,160,0,0.8,0,0.9,40,4,0.7,4,0.7};
   TF2 *f2 = new TF2("f2",fun2,-10,10,-10,10, npar);
   f2->SetParameters(f2params);

   //Create an histogram and fill it randomly with f2
   TH2F *h2 = new TH2F("h2","From f2",40,-10,10,40,-10,10);
   Int_t nentries = 100000;
   h2->FillRandom("f2",nentries);
   //Fit h2 with original function f2
   Float_t ratio = 4*nentries/100000;
   f2params[ 0] *= ratio;
   f2params[ 5] *= ratio;
   f2params[10] *= ratio;
   f2->SetParameters(f2params);
   h2->Fit("f2","N");
   TCutG *cutg = new TCutG("cutg",5);
   cutg->SetPoint(0,-7,-7);
   cutg->SetPoint(1, 2,-7);
   cutg->SetPoint(2, 2, 2);
   cutg->SetPoint(3,-7, 2);
   cutg->SetPoint(4,-7,-7);
   h2->Draw("lego2 0");
   h2->SetFillColor(38);
   f2->SetNpx(80);
   f2->SetNpy(80);
   f2->Draw("surf1 same bb [cutg]");
   return c;
}

{
   TCanvas *c06 = new TCanvas("c06","c06",600,400);
   gStyle->SetOptStat(kFALSE);
   TH3F *h3scat = new TH3F("h3scat","Option SCAT (default) ",15,-2,2,15,-2,2,15,0,4);
   Double_t x, y, z;
   for (Int_t i=0;i<10000;i++) {
      gRandom->Rannor(x, y);
      z = x*x + y*y;
      h3scat->Fill(x,y,z);
   }
   h3scat->Draw();
   return c06;
}

{
   TCanvas *c16 = new TCanvas("c16","c16",600,400);
   gStyle->SetOptStat(kFALSE);
   TH3F *h3box = new TH3F("h3box","Option BOX",15,-2,2,15,-2,2,15,0,4);
   Double_t x, y, z;
   for (Int_t i=0;i<10000;i++) {
      gRandom->Rannor(x, y);
      z = x*x + y*y;
      h3box->Fill(x,y,z);
   }
   h3box->Draw("BOX");
   return c16;
}

{
   TCanvas *c26 = new TCanvas("c26","c26",600,400);
   gStyle->SetOptStat(kFALSE);
   TH3F *h3iso = new TH3F("h3iso","Option ISO",15,-2,2,15,-2,2,15,0,4);
   Double_t x, y, z;
   for (Int_t i=0;i<10000;i++) {
      gRandom->Rannor(x, y);
      z = x*x + y*y;
      h3iso->Fill(x,y,z);
   }
   h3iso->SetFillColor(kCyan);
   h3iso->Draw("ISO");
   return c26;
}

TCanvas *hstack() {
// Example of stacked histograms: class THStack
//
//  Author: Rene Brun
   
   THStack *hs = new THStack("hs","Stacked 1D histograms");
   //create three 1-d histograms
   TH1F *h1st = new TH1F("h1st","test hstack",100,-4,4);
   h1st->FillRandom("gaus",20000);
   h1st->SetFillColor(kRed);
   h1st->SetMarkerStyle(21);
   h1st->SetMarkerColor(kRed);
   hs->Add(h1st);
   TH1F *h2st = new TH1F("h2st","test hstack",100,-4,4);
   h2st->FillRandom("gaus",15000);
   h2st->SetFillColor(kBlue);
   h2st->SetMarkerStyle(21);
   h2st->SetMarkerColor(kBlue);
   hs->Add(h2st);
   TH1F *h3st = new TH1F("h3st","test hstack",100,-4,4);
   h3st->FillRandom("gaus",10000);
   h3st->SetFillColor(kGreen);
   h3st->SetMarkerStyle(21);
   h3st->SetMarkerColor(kGreen);
   hs->Add(h3st);
   
   TCanvas *cst = new TCanvas("cst","stacked hists",10,10,700,700);
   cst->SetFillColor(41);
   cst->Divide(2,2);
   // in top left pad, draw the stack with defaults
   cst->cd(1);
   hs->Draw();
   // in top right pad, draw the stack in non-stack mode 
   // and errors option
   cst->cd(2);
   gPad->SetGrid();
   hs->Draw("nostack,e1p");
   //in bottom left, draw in stack mode with "lego1" option
   cst->cd(3);
   gPad->SetFrameFillColor(17);
   gPad->SetTheta(3.77);
   gPad->SetPhi(2.9);
   hs->Draw("lego1");

   cst->cd(4);
   //create two 2-D histograms and draw them in stack mode
   gPad->SetFrameFillColor(17);
   THStack *a = new THStack("a","Stacked 2D histograms");
   TF2 *f1 = new TF2("f1",
      "xygaus + xygaus(5) + xylandau(10)",-4,4,-4,4);
   Double_t params[] = {130,-1.4,1.8,1.5,1, 150,2,0.5,-2,0.5, 
      3600,-2,0.7,-3,0.3};
   f1->SetParameters(params);
   TH2F *h2sta = new TH2F("h2sta","h2sta",20,-4,4,20,-4,4);
   h2sta->SetFillColor(38);
   h2sta->FillRandom("f1",4000);
   TF2 *f2 = new TF2("f2","xygaus + xygaus(5)",-4,4,-4,4);
   Double_t params[] = {100,-1.4,1.9,1.1,2, 80,2,0.7,-2,0.5};
   f2->SetParameters(params);
   TH2F *h2stb = new TH2F("h2stb","h2stb",20,-4,4,20,-4,4);
   h2stb->SetFillColor(46);
   h2stb->FillRandom("f2",3000);
   a->Add(h2sta);
   a->Add(h2stb);
   a->Draw();
   return cst;
}

{
   TCanvas *cst1 = new TCanvas("cst1","cst1",700,400);
   cst1->Divide(2,1);

   TH1F * hst11 = new TH1F("hst11", "", 20, -10, 10);
   hst11->Sumw2();
   hst11->FillRandom("gaus", 1000);
   hst11->SetFillColor(kViolet);
   hst11->SetLineColor(kViolet);

   TH1F * hst12 = new TH1F("hst12", "", 20, -10, 10);
   hst12->FillRandom("gaus", 500);
   hst12->SetFillColor(kBlue);
   hst12->SetLineColor(kBlue);

   THStack st1("st1", "st1");
   st1.Add(hst11);
   st1.Add(hst12);

   cst1->cd(1); st1.Draw();
   cst1->cd(2); st1.Draw("hist");

   return cst1;
}

{
   TCanvas *c2 = new TCanvas("c2","c2",600,400);
   TF3 *f3 = new TF3("f3","sin(x*x+y*y+z*z-36)",-2,2,-2,2,-2,2);
   f3->SetClippingBoxOn(0,0,0);
   f3->SetFillColor(30);
   f3->SetLineColor(15);
   f3->Draw("FBBB");
   return c2;
}