{
gROOT->Reset();

// -- Nothing fancy
gROOT->SetStyle("Plain");
gROOT->ForceStyle();

// -- Don't show histogram titles
gStyle->SetOptTitle(0);

// -- Open the File
TFile f("Exercise3.root");

// -- Remove stats box
gStyle->SetOptStat(0);

// -- Define and fill histograms containing the sum and ratio 
TH1F *hsum1 = new TH1F(*h1d1);
TH1F *hsum2 = new TH1F(*h1d1);
TH1F *hratio = new TH1F(*h1d1);

hsum1->Add(h1d1, h1d2);
hsum2->Add(hsum1, h1d2);
hratio->Divide(h1d1, h1d2);

// -- Change the appearance
hsum2->SetFillColor(kBlue);
hsum1->SetFillColor(kGreen);
h1d1->SetFillColor(kRed);

// -- Provide some labelling
hsum2->SetAxisRange(0., 8.);
hsum2->SetTitleOffset(1.2, "y"); hsum2->SetXTitle("Charged Track Mulitiplicity");   
hsum2->SetTitleOffset(1.2, "x"); hsum2->SetYTitle("Entries/bin");

// -- Draw them. Redraw the axes at the end
hsum2->Draw();
hsum1->Draw("Same");
h1d1->Draw("Same");
hsum2->Draw("sameaxis");

// -- Make an inset and show the ratio
TPad *npad = new TPad("npad", "", 0.6, 0.6, 0.9, 0.88);
npad->Draw();
npad->cd();

gPad->SetGridx(1);  gPad->SetGridy(1); 

// -- make enough space so that axis titles are not cut off
gPad->SetBottomMargin(0.25);
gPad->SetLeftMargin(0.25);

// -- labelling
hratio->SetLabelSize(0.1, "x");   
hratio->SetLabelSize(0.1, "y");   
hratio->SetNdivisions(305);

hratio->SetTitleSize(0.105, "y"); hratio->SetTitleOffset(.8, "y");  hratio->SetYTitle("Positive/Negative");
hratio->SetTitleSize(0.1, "x"); hratio->SetTitleOffset(1.2, "x");  hratio->SetXTitle("Multiplitcity");

// -- show a subrange
hratio->SetMaximum(3.);
hratio->SetAxisRange(0., 8.);
hratio->Draw();


// -- go back to the big canvas and put a legend there
c1->cd();

TLegend *pl = new TLegend(0.6,0.25,0.88,0.5);
pl->SetTextSize(0.03); 
pl->SetFillColor(0);
TLegendEntry *ple = pl->AddEntry(h1d1, "Positive GoodTracks",  "F"); 
ple = pl->AddEntry(hsum1, "Negative GoodTracks",  "F");
ple = pl->AddEntry(hsum2, "Charged tracks",  "F");
pl->Draw();


// -- Save it to files
c1->SaveAs("inset.eps");
c1->SaveAs("inset.gif");

}