text: import pylab
  import tables
  import math
  import numpy
  pylab.rc('text', usetex=True)
  
  NT = 100
  Ey_tx = numpy.zeros( (NT+1, 400), numpy.float )
  for i in range(NT+1):
      fh = tables.openFile("s69-plasmabeach_q_%d.h5" % i)
      q = fh.root.StructGridField
      Ey = q[:,11]
      Ey_tx[i,:] = Ey
  
  dx = 1/400.0
  X = pylab.linspace(0.5*dx, 1-0.5*dx, 400)
  T = pylab.linspace(0, 5e-9, NT+1)
  TT, XX = pylab.meshgrid(T, X)
  
  # compute cutoff location
  dx100 = 1/100.
  deltaT = dx100/2.99792458e8
  driveOmega = 3.14159265358979323846264338328/10/deltaT
  xcutoff = 1-math.pow(driveOmega/25*deltaT, 1/5.0)
  
  pylab.pcolormesh(TT, XX, Ey_tx.transpose())
  pylab.plot([0, 5e-9], [xcutoff, xcutoff], 'k--', linewidth=2)
  pylab.xlabel('Time [s]')
  pylab.ylabel('X [m]')
  pylab.title(r'$E_y(t,x)$')
  pylab.savefig('s69-plasmabeach_Ey.png')
  pylab.show()
  