import ROOT


# Set up model
# ---------------------

# Create observables
x = ROOT.RooRealVar("x", "x", -10, 10)

# Create Gaussian
sigma = ROOT.RooRealVar("sigma", "sigma", 3, 0.1, 10)
mean = ROOT.RooRealVar("mean", "mean", -3, -10, 10)
gauss = ROOT.RooGaussian("gauss", "gauss", x, mean, sigma)

# Generate a sample of 100 events with sigma=3
data = gauss.generate({x}, 100)

# Fit pdf to data
gauss.fitTo(data, PrintLevel=-1)

# Make plot frames
# -------------------------------

# Make four plot frames to demonstrate various plotting features
frame1 = x.frame(Name="xframe", Title="Red Curve / SumW2 Histo errors", Bins=20)
frame2 = x.frame(Name="xframe", Title="Dashed Curve / No XError bars", Bins=20)
frame3 = x.frame(Name="xframe", Title="Filled Curve / Blue Histo", Bins=20)
frame4 = x.frame(Name="xframe", Title="Partial Range / Filled Bar chart", Bins=20)

# Data plotting styles
# ---------------------------------------

# Use sqrt(sum(weights^2)) error instead of Poisson errors
data.plotOn(frame1, DataError="SumW2")

# Remove horizontal error bars
data.plotOn(frame2, XErrorSize=0)

# Blue markers and error bors
data.plotOn(frame3, MarkerColor="b", LineColor="b")

# Filled bar chart
data.plotOn(frame4, DrawOption="B", DataError=None, XErrorSize=0, FillColor="kGray")

# Function plotting styles
# -----------------------------------------------

# Change line color to red
gauss.plotOn(frame1, LineColor="r")

# Change line style to dashed
gauss.plotOn(frame2, LineStyle="--")

# Filled shapes in green color
gauss.plotOn(frame3, MoveToBack=True, DrawOption="F", FillColor="kOrange")

#
gauss.plotOn(frame4, Range=(-8, 3), LineColor="m")

c = ROOT.TCanvas("rf107_plotstyles", "rf107_plotstyles", 800, 800)
c.Divide(2, 2)
c.cd(1)
ROOT.gPad.SetLeftMargin(0.15)
frame1.GetYaxis().SetTitleOffset(1.6)
frame1.Draw()
c.cd(2)
ROOT.gPad.SetLeftMargin(0.15)
frame2.GetYaxis().SetTitleOffset(1.6)
frame2.Draw()
c.cd(3)
ROOT.gPad.SetLeftMargin(0.15)
frame3.GetYaxis().SetTitleOffset(1.6)
frame3.Draw()
c.cd(4)
ROOT.gPad.SetLeftMargin(0.15)
frame4.GetYaxis().SetTitleOffset(1.6)
frame4.Draw()

c.SaveAs("rf107_plotstyles.png")