Logo ROOT   master
Reference Guide
ntuple1.py File Reference

Namespaces

 ntuple1
 

Detailed Description

View in nbviewer Open in SWAN Ntuple drawing example.

from ROOT import TCanvas, TPad, TFile, TPaveText
from ROOT import gBenchmark, gStyle, gROOT
c1 = TCanvas('c1','The Ntuple canvas',200,10,700,780)
gBenchmark.Start('ntuple1')
#
# Connect ROOT histogram/ntuple demonstration file
# generated by example hsimple.C.
f1 = TFile('py-hsimple.root')
#
# Inside this canvas, we create 4 pads
pad1 = TPad('pad1','This is pad1',0.02,0.52,0.48,0.98,21)
pad2 = TPad('pad2','This is pad2',0.52,0.52,0.98,0.98,21)
pad3 = TPad('pad3','This is pad3',0.02,0.02,0.48,0.48,21)
pad4 = TPad('pad4','This is pad4',0.52,0.02,0.98,0.48,1)
pad1.Draw()
pad2.Draw()
pad3.Draw()
pad4.Draw()
#
# Change default style for the statistics box
gStyle.SetStatW(0.30)
gStyle.SetStatH(0.20)
gStyle.SetStatColor(42)
#
# Display a function of one ntuple column imposing a condition
# on another column.
pad1.cd()
pad1.SetGrid()
pad1.SetLogy()
pad1.GetFrame().SetFillColor(15)
ntuple = gROOT.FindObject('ntuple')
ntuple.SetLineColor(1)
ntuple.SetFillStyle(1001)
ntuple.SetFillColor(45)
ntuple.Draw('3*px+2','px**2+py**2>1')
ntuple.SetFillColor(38)
ntuple.Draw('2*px+2','pz>2','same')
ntuple.SetFillColor(5)
ntuple.Draw('1.3*px+2','(px^2+py^2>4) && py>0','same')
c1.Update()
#
# Display the profile of two columns
# The profile histogram produced is saved in the current directory with
# the name hprofs
pad2.cd()
pad2.SetGrid()
pad2.GetFrame().SetFillColor(32)
ntuple.Draw('pz:px>>hprofs','','goffprofs')
hprofs = gROOT.FindObject('hprofs')
hprofs.SetMarkerColor(5)
hprofs.SetMarkerSize(0.7)
hprofs.SetMarkerStyle(21)
hprofs.Fit('pol2')
#
# Get pointer to fitted function and modify its attributes
fpol2 = hprofs.GetFunction('pol2')
fpol2.SetLineWidth(4)
fpol2.SetLineColor(2)
c1.Update()
#
# Display a scatter plot of two columns with a selection.
# Superimpose the result of another cut with a different marker color
pad3.cd()
pad3.GetFrame().SetFillColor(38)
pad3.GetFrame().SetBorderSize(8)
ntuple.SetMarkerColor(1)
ntuple.Draw('py:px','pz>1')
ntuple.SetMarkerColor(2)
ntuple.Draw('py:px','pz<1','same')
c1.Update()
#
# Display a 3-D scatter plot of 3 columns. Superimpose a different selection.
pad4.cd()
ntuple.Draw('pz:py:px','(pz<10 && pz>6)+(pz<4 && pz>3)')
ntuple.SetMarkerColor(4)
ntuple.Draw('pz:py:px','pz<6 && pz>4','same')
ntuple.SetMarkerColor(5)
ntuple.Draw('pz:py:px','pz<4 && pz>3','same')
l4 = TPaveText(-0.9,0.5,0.9,0.95)
l4.SetFillColor(42)
l4.SetTextAlign(12)
l4.AddText('You can interactively rotate this view in 2 ways:')
l4.AddText(' - With the RotateCube in clicking in this pad')
l4.AddText(' - Selecting View with x3d in the View menu')
l4.Draw()
#
# done
c1.cd()
c1.Update()
gStyle.SetStatColor(19)
gBenchmark.Show('ntuple1')
Author
Wim Lavrijsen

Definition in file ntuple1.py.