#! /usr/bin/env python3
#
def wave_2d_test ( ):

  import numpy as np
  import matplotlib.pyplot as plt
  import matplotlib.animation as animation
  from wave_eqn2d import WaveEqn2D

  A = 80
  dt = 1
  T = 50
  freq = 2 * np.pi / T
  nx = 200
  ny = 200
  sim = WaveEqn2D ( nx, ny, dt = dt, use_mur_abc = True )
  fig, ax = plt.subplots()
  ax.axis ( "off" )
  img = ax.imshow ( sim.u[0], vmin=0.0, vmax=40.0, cmap='Blues_r' )

  def update(i):
    """Advance the simulation by one tick."""
# A regular sinusoidal signal at the center of the domain.
    sim.u[0, ny//2, nx//2] = A * np.sin ( i * freq )
    sim.update()

  def init():
    """
    Initialization, because we're blitting and need references to the
    animated objects.
    """
    return img,

  def animate(i):
    """Draw frame i of the animation."""
    update ( i )
    img.set_data ( sim.u[0] )
    return img,

  interval = sim.dt
  nframes = 1000
  ani = animation.FuncAnimation ( fig, animate, frames=nframes, repeat=False, \
    init_func=init, interval=interval, blit=True )
  plt.show()

  return

if ( __name__ == "__main__" ):
  wave_2d_test ( )