#!/usr/bin/env python
# coding: utf-8

# <img src="http://files.oproject.org/img/HeaderOpenData.png">
# 
# # ROOT Basics
# ## Import Required Modules and Turn on Javascript

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from ROOT import TFile, TCanvas, TH1F

get_ipython().run_line_magic('jsroot', 'on')


# ## Open a Data File

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file = TFile("opendata/data/Dimuons.root","READ")


# ## Declare a Histogram
# ### Histogram is a Graphical Way to Visualize Data
# <img src="https://s3.amazonaws.com/engrade-myfiles/4012104668779794/iw_histogram.gif"></img>
# #### Divide Data into Equal Intervals (Bins) and Count How Many Values in Each Bin
# 
# 

# ## Example Histogram of Distribution of Muon Charges

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histogram = TH1F("Muon1_Charge","Muon1_Charge", 50, -2, 2)


# ### declaration format: TH1F(name, title, number of bins, min value, max value)
# ## ROOT Exercise 1: 
# ## Declare another histogram for x-component of muon momentum called Muon1_Px
# 

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histogram2 = TH1F("Muon1_Px","Muon1_Px", 100, -60, 60)


# ## Loop Over Events in Data File

# Fill the histogram with muon charge values (+1 or -1)

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for dimuon in file.Dimuons:
    
    histogram.Fill(dimuon.Muon1_Charge)       


# ## Draw a Histogram on a Canvas

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Canvas = TCanvas()

histogram.Draw()

Canvas.Draw()


# ## ROOT Exercise #2: 
# ### Plot another histogram  (for example Muon1_Px)
# Note: Same canvas can be used after clearing it with Canvas.Clear() 

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for dimuon in file.Dimuons:
    histogram2.Fill(dimuon.Muon1_Px)


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Canvas.Clear()
histogram2.Draw()
Canvas.Draw()


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