# Reading Pthia8 file in the ProMC format using [[http://jwork.org/dmelt | DataMelt]]
# S.Chekanov (ANL)
from java.io import *
from java.awt import *
from promc.io import *
from proto import *   # import FileMC
from jhplot import *  # import DatMelt graphics

file = FileMC("Pythia8.promc")
print "ProMC version=",file.getVersion()
print "Last Modified=",file.getLastModified()
header = file.getHeader()                     # get header file
unit=float(header.getMomentumUnit())
lunit=float(header.getLengthUnit())
print "Momentum unit=",unit
print "Length unit=",lunit

for j in range(header.getParticleDataCount()): # look at PDG info stored in the header
  d = header.getParticleData(j)
  pid = d.getId(); mass = d.getMass(); name = d.getName();
  print name, pid, mass

h1= H1D("Px",100,0,10)   # create a histogram
print "File size=",file.size()

for i in range(file.size()):  # run over all events    
      if (i%100==0): print "Event=",i
      entry = file.read(i)
      p = entry.getParticles()                 # get particles
      for j in range( p.getPxCount() ):
            h1.fill(p.getPx(j)/unit)
c1 = HPlot("Canvas",600,400) # plot histogram
c1.visible()
c1.setAutoRange()
c1.draw(h1)
c1.export("px.pdf")                          # create PDF file