# Calculate cross sections for gamma events
# S.Chekanov
from jhplot import *
from jhplot.io import*

c1=HPlot("X-cross",600,400,2,1)
c1.visible()
c1.setAutoRange()

f=PFile("main02.pbu")
print f.listEntries()

# read histograms using keys
h1=f.read("pT(gamma)")
h2=f.read("eta(gamma)")

# get number of events and lumi
events=f.read("events")
cross=f.read("cross")
print "Tot events=",events
print "Tot cross=",cross
lumi=events.get(0)/cross.get(0)
print "Lumi (pb-1)=",lumi

# calculate scaling factors for cross sections
scale1=lumi*h1.getBinSize()
scale2=lumi*h2.getBinSize()
print scale1,scale2

# scale to get differential cross sections
h1.scale(1.0/scale1)
h2.scale(1.0/scale2)

# PT plot
c1.cd(1,1)
c1.setAutoRange()
c1.setLogScale(1,1)
c1.draw(h1)

# eta plot
c1.cd(2,1)
c1.setAutoRange()
c1.draw(h2)

# generate EPS figure
c1.export("xcross.eps")