From c3e7684bb1c22616c93ac5f8f38e897b47851984 Mon Sep 17 00:00:00 2001
From: Juan Fernando Jaramillo Botero <juanf.jaramillo@opdevel.com>
Date: Thu, 3 May 2018 10:18:31 -0500
Subject: [PATCH] Translate tStudent.C to Python
Add tStudent.py to the list of math tutorials.
---
tutorials/CMakeLists.txt | 1 +
tutorials/math/tStudent.py | 83 ++++++++++++++++++++++++++++++++++++++
2 files changed, 84 insertions(+)
create mode 100644 tutorials/math/tStudent.py
diff --git a/tutorials/CMakeLists.txt b/tutorials/CMakeLists.txt
index b83afd4a8aa..0e338d4c06e 100644
--- a/tutorials/CMakeLists.txt
+++ b/tutorials/CMakeLists.txt
@@ -381,6 +381,7 @@ if(ROOT_python_FOUND)
if(NOT ROOT_mathmore_FOUND)
list(APPEND pyveto math/Legendre.py)
list(APPEND pyveto math/Bessel.py)
+ list(APPEND pyveto math/tStudent.py)
endif()
list(REMOVE_ITEM pytutorials ${pyveto})
diff --git a/tutorials/math/tStudent.py b/tutorials/math/tStudent.py
new file mode 100644
index 00000000000..fe920c843a7
--- /dev/null
+++ b/tutorials/math/tStudent.py
@@ -0,0 +1,83 @@
+## \file
+## \ingroup tutorial_math
+## \notebook
+## Example macro describing the student t distribution
+##
+## ~~~{.cpp}
+## root[0]: .x tStudent.C
+## ~~~
+##
+## It draws the pdf, the cdf and then 10 quantiles of the t Student distribution
+##
+## based on Magdalena Slawinska's tStudent.C
+##
+## \macro_image
+## \macro_code
+##
+## \author Juan Fernando Jaramillo Botero
+
+from ROOT import TH1D, TF1, TCanvas, kRed, kBlue
+import ROOT
+
+
+# This is the way to force load of MathMore in Cling
+ROOT.Math.MathMoreLibrary.Load()
+
+# Create the pdf and the cumulative distributions
+n = 100
+a = -5.
+b = 5.
+pdf = TF1("pdf", "ROOT::Math::tdistribution_pdf(x,3.0)", a, b)
+cum = TF1("cum", "ROOT::Math::tdistribution_cdf(x,3.0)", a, b)
+
+# Create the histogram and fill it with the quantiles
+quant = TH1D("quant", "", 9, 0, 0.9)
+
+for i in range(1, 10):
+ quant.Fill((i-0.5)/10.0, ROOT.Math.tdistribution_quantile(0.1 * i,
+ 3.0))
+
+# For each quantile fill with the pdf
+xx = [-1.5] + [quant.GetBinContent(i)for i in range(1, 9)] + [1.5]
+pdfq = []
+for i in range(9):
+ nbin = int(n * (xx[i+1] - xx[i]) / 3.0 + 1.0)
+ name = "pdf%d" % i
+ pdfq.append(TH1D(name, "", nbin, xx[i], xx[i+1]))
+ for j in range(1, nbin):
+ x = j * (xx[i+1] - xx[i]) / nbin + xx[i]
+ pdfq[i].SetBinContent(j, ROOT.Math.tdistribution_pdf(x, 3))
+
+# Create the Canvas and divide in four draws, for every draw set the line width
+# the title, and the line color.
+Canvas = TCanvas("DistCanvas", "Student Distribution graphs", 10, 10, 800, 700)
+pdf.SetTitle("Student t distribution function")
+cum.SetTitle("Cumulative for Student t")
+quant.SetTitle("10-quantiles for Student t")
+Canvas.Divide(2, 2)
+Canvas.cd(1)
+pdf.SetLineWidth(2)
+pdf.DrawCopy()
+Canvas.cd(2)
+cum.SetLineWidth(2)
+cum.SetLineColor(kRed)
+cum.Draw()
+Canvas.cd(3)
+quant.Draw()
+quant.SetLineWidth(2)
+quant.SetLineColor(kBlue)
+quant.SetStats(0)
+Canvas.cd(4)
+pdfq[0].SetTitle("Student t & its quantiles")
+pdf.SetTitle("")
+pdf.Draw()
+pdfq[0].SetTitle("Student t & its quantiles")
+
+# Set the colors in every quantile.
+i = 1
+for pd in pdfq[1:]:
+ pd.SetStats(0)
+ i += 1
+ pd.SetFillColor(i)
+ pd.Draw("same")
+Canvas.Modified()
--
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