#!/usr/bin/python
import os,sys
from ROOT import *

L1 = 1E-6  #metal
L2 = 30E-6 #gas
fast_depol = 0.01 #gas
fr = 0.25  #fraction stopping in gas

fu1 = '1.00 * exp(-1.*'+str(L1)+'*x)'
fu2 = str(1-fast_depol)+'* exp(-1.*'+str(L2)+'*x)'
fu3 = str(1-fr)+'*'+fu1+' + '+str(fr)+'*'+fu2

f1 = TF1('f1',fu1,-1.,10000.0)
f2 = TF1('f2',fu2,-1.,10000.0)
f3 = TF1('f3',fu3,-1.,10000.0)

f1.SetLineColor(1)
f2.SetLineColor(2)
f3.SetLineColor(4)

c1 = TCanvas('c1','c1')

f1.Draw()
f2.Draw('same')
f3.Draw('same')

c2 = TCanvas('c2','c2')

gr = TGraph()
for i in range(100):
    t = 100*i
    gr.SetPoint(i,t,(1-fr)*(1.00*exp(-1.*L1*t))+fr*((1-fast_depol)*exp(-1.*L2*t)))

gr.SetMarkerStyle(20)
#p1_r = TF1('p1_r','pol1',1000.,10000.)
#gr.Fit('p1_r','R')

def my_exp(x,par): return par[0]*exp(-1*par[1]*x[0])
tf_exp = TF1('tf_exp', my_exp, 1000., 10000., 2 )

gr.Fit(tf_exp,'R','',1000.,10000.)

gr.Draw("AP")

au = raw_input('>')