Graficando oscilaciones

import numpy as np
import math
import matplotlib.pyplot as plt



Nx	=	200

l0	=	1.0e-9
k	=	(2.0*math.pi)/l0

ex	=	np.zeros(Nx)

xi	=	0
xf	=	10*l0
dx	=	(xf-xi)/Nx

for ix in range(1,Nx):
  x	=	xi+ix*dx
  ex[ix]=math.sin(k*x)
  
plt.plot(ex,color='k',linewidth=1)
plt.savefig("ex.png")
plt.close()

import numpy as np
import math
import matplotlib.pyplot as plt

#from datetime import datetime
#start_time = datetime.now()

c	=	3e8
Nx	=	200

l0	=	1.0e-9
t0	=	l0/c

k	=	(2.0*math.pi)/l0
w	=	(2.0*math.pi)/t0


ex	=	np.zeros(Nx)

xi	=	0
xf	=	10*l0
dx	=	(xf-xi)/Nx

Nt	=	99
ti	=	0
tf	=	10*t0
dt	=	(tf-ti)/Nt

for it in range(1,Nt):
  t	=	ti+it*dt
  for ix in range(0,Nx):
    x	=	xi+ix*dx
    ex[ix]=math.sin(k*x-w*t)  
  plt.plot(ex,color='k',linewidth=1)
  if it<  10:plt.savefig("ex0{}.png".format(it))
  if it>= 10:plt.savefig("ex{}.png".format(it)) 
  plt.close()
  
  
#end_time = datetime.now()
#print('Duration: {}'.format(end_time - start_time))