Draw a scatter plot for 4 variables, mapped to: x, y, marker colour and marker size. 
TScatter is available since ROOT v.6.30. See the TScatter documentation
  
import numpy as np
import ROOT
 
 
n = 175
 
 
 
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
 
  - Author
 - Olivier Couet, Jamie Gooding 
 
Definition in file gr006_scatter.py.