# -*- coding: utf-8 -*-

import math
from numpy import arange
import numpy as numpy
from matplotlib.pyplot import  plot, show
import matplotlib.pyplot as plt

t = arange(0.0, 12.0, 0.01)

s = []
for a in t[0:numpy.size(t)/2]:
	s.append(1-numpy.exp(-a))
for b in t[numpy.size(t)/2+0.01:1200]:
	s.append(numpy.exp(-b+6))
	
e = [0]
i = 1
while i != 6/0.01:
	e.append(1)
	i += 1
while i != 12/0.01:
	e.append(0)
	i+=1
	
fig = plt.figure()
ax1 = fig.add_subplot(111)
ax1.set_ylabel('Tension (volts)')
ax1.plot(t,e,"b--")

ax2 = fig.add_subplot(111)
ax2.set_xlabel('Temps (secondes)')
ax2.plot(t,s,"r")

plt.axis([0,12,0,1.1])
plt.grid(True)
plt.legend((u"Échelon de tension","Tension aux bornes du condensateur"),loc="lower right")
plt.savefig('charge_decharge_condensateur.svg' ,transparent=False)