def rooFit206():
print ">>> setup model signal components: gaussians..."
x = RooRealVar("x", "x", 0, 10)
mean = RooRealVar("mean", "mean of gaussians", 5)
sigma1 = RooRealVar("sigma1", "width of gaussians", 0.5)
sigma2 = RooRealVar("sigma2", "width of gaussians", 1)
sig1 = RooGaussian("sig1", "Signal component 1", x, mean, sigma1)
sig2 = RooGaussian("sig2", "Signal component 2", x, mean, sigma2)
sig1frac = RooRealVar("sig1frac", "fraction of component 1 in signal", 0.8,
0., 1.)
sig = RooAddPdf("sig", "Signal", RooArgList(sig1, sig2),
RooArgList(sig1frac))
print ">>> setup model background components: Chebychev polynomial plus exponential..."
a0 = RooRealVar("a0", "a0", 0.5, 0., 1.)
a1 = RooRealVar("a1", "a1", -0.2, 0., 1.)
bkg1 = RooChebychev("bkg1", "Background 1", x, RooArgList(a0, a1))
alpha = RooRealVar("alpha", "alpha", -1)
bkg2 = RooExponential("bkg2", "Background 2", x, alpha)
bkg1frac = RooRealVar("bkg1frac", "fraction of component 1 in background",
0.2, 0., 1.)
bkg = RooAddPdf("bkg", "Signal", RooArgList(bkg1, bkg2),
RooArgList(bkg1frac))
print ">>> sum signal and background component..."
bkgfrac = RooRealVar("bkgfrac", "fraction of background", 0.5, 0., 1.)
model = RooAddPdf("model", "g1+g2+a", RooArgList(bkg, sig),
RooArgList(bkgfrac))
print ">>> composite tree in ASCII:"
model.Print("t")
print "\n>>> write to txt file"
model.printCompactTree("", "rooFit206_asciitree.txt")
print ">>> draw composite tree graphically..."
# Print GraphViz DOT file with representation of tree
model.graphVizTree("rooFit206_model.dot")
# Make graphic output file with one of the GraphViz tools
# (freely available from www.graphviz.org)
#
# 'Top-to-bottom graph'
# unix> dot -Tgif -o rooFit206_model_dot.gif rooFit206_model.dot
#
# 'Spring-model graph'
# unix> fdp -Tgif -o rooFit206_model_fdp.gif rooFit206_model.dot
print ">>> plot everything..."
data = model.generate(RooArgSet(x), 1000) # RooDataSet
frame1 = x.frame(
Title("Component plotting of pdf=(sig1+sig2)+(bkg1+bkg2)")) # RooPlot
data.plotOn(frame1, Name("data"), Binning(40))
model.plotOn(frame1, Name("model"))
argset1 = RooArgSet(bkg)
argset2 = RooArgSet(bkg2)
argset3 = RooArgSet(bkg, sig2)
model.plotOn(frame1, Components(argset1), LineColor(kRed), Name("bkg"))
model.plotOn(frame1, Components(argset2), LineStyle(kDashed),
LineColor(kRed), Name("bkg2"))
model.plotOn(frame1, Components(argset3), LineStyle(kDotted),
Name("bkgsig2"))
print "\n>>> draw pfds and fits on canvas..."
canvas = TCanvas("canvas", "canvas", 100, 100, 800, 600)
legend = TLegend(0.22, 0.85, 0.4, 0.65)
legend.SetTextSize(0.032)
legend.SetBorderSize(0)
legend.SetFillStyle(0)
gPad.SetLeftMargin(0.15)
gPad.SetRightMargin(0.02)
frame1.GetYaxis().SetLabelOffset(0.008)
frame1.GetYaxis().SetTitleOffset(1.6)
frame1.GetYaxis().SetTitleSize(0.045)
frame1.GetXaxis().SetTitleSize(0.045)
frame1.Draw()
legend.AddEntry("data", "data", 'LEP')
legend.AddEntry("model", "model", 'L')
legend.AddEntry("bkg", "bkg", 'L')
legend.AddEntry("bkg2", "bkg2", 'L')
legend.AddEntry("bkgsig2", "bkg,sig2", 'L')
legend.Draw()
canvas.SaveAs("rooFit206.png")
