H 1Draw

A Simple histogram drawing example

Author: Wim Lavrijsen
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Thursday, June 04, 2020 at 02:45 AM.

In [ ]:
from ROOT import TCanvas, TPad, TFile, TPaveLabel, TPaveText
from ROOT import gROOT

c1 = TCanvas( 'c1', 'Histogram Drawing Options', 200, 10, 700, 900 )

pad1 = TPad( 'pad1', 'The pad with the function',  0.03, 0.62, 0.50, 0.92, 21 )
pad2 = TPad( 'pad2', 'The pad with the histogram', 0.51, 0.62, 0.98, 0.92, 21 )
pad3 = TPad( 'pad3', 'The pad with the histogram', 0.03, 0.02, 0.97, 0.57, 21 )
pad1.Draw()
pad2.Draw()
pad3.Draw()

We connect the ROOT file generated in a previous tutorial

In [ ]:
example = TFile( 'py-hsimple.root' )
example.ls()

Draw a global picture title

In [ ]:
title = TPaveLabel( 0.1, 0.94, 0.9, 0.98,
                    'Drawing options for one dimensional histograms' )
title.SetFillColor( 16 )
title.SetTextFont( 52 )
title.Draw()

Draw histogram hpx in first pad with the default option.

In [ ]:
pad1.cd()
pad1.GetFrame().SetFillColor( 18 )
hpx = gROOT.FindObject( 'hpx' )
hpx.SetFillColor( 45 )
hpx.DrawCopy()
label1 = TPaveLabel( -3.5, 700, -1, 800, 'Default option' )
label1.SetFillColor( 42 )
label1.Draw()

Draw hpx as a lego. Clicking on the lego area will show a "transparent cube" to guide you rotating the lego in real time.

In [ ]:
pad2.cd()
hpx.DrawCopy( 'lego1' )
label2 = TPaveLabel( -0.72, 0.74, -0.22, 0.88, 'option Lego1' )
label2.SetFillColor( 42 )
label2.Draw()
label2a = TPaveLabel( -0.93, -1.08, 0.25, -0.92, 'Click on lego to rotate' )
label2a.SetFillColor( 42 )
label2a.Draw()

Draw hpx with its errors and a marker.

In [ ]:
pad3.cd()
pad3.SetGridx()
pad3.SetGridy()
pad3.GetFrame().SetFillColor( 18 )
hpx.SetMarkerStyle( 21 )
hpx.Draw( 'e1p' )
label3 = TPaveLabel( 2, 600, 3.5, 650, 'option e1p' )
label3.SetFillColor( 42 )
label3.Draw()

The following illustrates how to add comments using a PaveText. Attributes of text/lines/boxes added to a PaveText can be modified. The AddText function returns a pointer to the added object.

In [ ]:
pave = TPaveText( -3.78, 500, -1.2, 750 )
pave.SetFillColor( 42 )
t1 = pave.AddText( 'You can move' )
t1.SetTextColor( 4 )
t1.SetTextSize( 0.05 )
pave.AddText( 'Title and Stats pads' )
pave.AddText( 'X and Y axis' )
pave.AddText( 'You can modify bin contents' )
pave.Draw()
c1.Update()

Draw all canvases

In [ ]:
%jsroot on
from ROOT import gROOT 
gROOT.GetListOfCanvases().Draw()