def set_receptors_firing_rate(x, y, theta, err_l, err_r, arena):
"""
Set the firing rate of the 18 neural receptors according to the
robot's current view and the error in wheel speeds.
@param x: Robot's current x position.
@param y: Robot's current y position.
@param theta: Robot's current orientation angle.
@param err_l: Error between desired and actual speed in the left
wheel.
@param err_r: Error between desired and actual speed in the right
wheel.
"""
il, ir = vision.get_visible_wall_coordinates(x, y, theta, arena)
view_proportion = vision.get_walls_view_ratio(il, ir, x, y, theta, arena)
view = vision.get_view(x, y, il, ir, view_proportion, arena)
if len(view) != 64:
print len(view), il, ir, view_proportion
# Input pixels
px = view[::4]
while len(px) > 16:
print len(px)
px = np.delete(px, -1)
px = vision.add_noise_to_pixels(px)
px = list(np.abs(vision.laplace_filter(px)))
px = vision.scale_list(px)
simtime = nest.GetKernelStatus()['time']
# Update the 16 spike generators representing the visual
# input according to the pixel values read
for i in range(len(px)):
if np.random.rand() < px[i]:
nest.SetStatus([i+11], {'spike_times': [simtime + 1]})
# Set random rates for the two spike generators representing the
# error in wheel speeds.
if np.random.rand() < err_l:
nest.SetStatus([27],
{'spike_times': [simtime + 1]})
if np.random.rand() < err_r:
nest.SetStatus([28],
{'spike_times': [simtime + 1]})
return px
