# Loading the two graphs
canvas = ROOT.TCanvas("FpixBpixCanvas")
graph = ROOT.TMultiGraph("FpixBpix", "Efficiency vs delay on FPix, BPix;delay(WBC setting + ns);efficiency")
clusterHistoAsGraph = (...) # Some TGraph objects
efficiencyAsGraph   = (...) # Some TGraph objects

# Creating the first graph
graph.Add(clusterHistoAsGraph)

# Creating two overlaying TPads
p1 = ROOT.TPad("p1", "", 0, 0, 1, 1)
p1.SetGrid()
p2 = ROOT.TPad("p2", "", 0, 0, 1, 1)
p1.SetFillStyle(4000)
p1.Draw()
p1.cd()

# Drawing the first graph
graph.Draw("0AP")
gPad.Update()

# Styling the range-axis
graph.GetXaxis().SetLabelOffset(0.0)
graph.GetXaxis().CenterTitle()
graph.GetXaxis().SetTitleOffset(3.3)
graph.GetXaxis().Set(8, 162, 163.6)
graph.GetXaxis().SetNdivisions(-508)

# Styling the first value axis
graph.GetYaxis().SetTitle("Avg. on track  cluster size")
graph.GetYaxis().SetLabelSize(0.035)
graph.GetYaxis().SetLabelFont(42)
graph.GetYaxis().SetTitleFont(42)

# Creating and styling the second value axis
secondaryAxis = ROOT.TGaxis(DELAY_PLOTS_UPPER_EDGE, gPad.GetUymin(), DELAY_PLOTS_UPPER_EDGE, gPad.GetUymax(), 0, 1.2, 50510, "+L")
secondaryAxis.SetTitle("Hit Efficiency")
secondaryAxis.SetLabelOffset(0.012)
secondaryAxis.SetLabelSize(0.035)
secondaryAxis.SetTextFont(42)
secondaryAxis.SetLabelFont(42)
secondaryAxis.SetLabelColor(ROOT.kBlue)
secondaryAxis.SetTitleColor(ROOT.kBlue)
secondaryAxis.SetLineColor(ROOT.kBlue)

# Drawing the second graph
p2.Draw()
p2.cd()
efficiencyAsGraph.Draw("P0")
gPad.Update()

# Drawing everything
canvas.Draw()
secondaryAxis.Draw()
label = ROOT.TLatex()
label.SetTextAlign(22)
label.DrawLatexNDC(0.50 + canvas.GetRightMargin() / 2 - canvas.GetLeftMargin() / 2, 0.5 + canvas.GetBottomMargin() / 2 - canvas.GetTopMargin() / 2, "BPix");