from matplotlib import pyplot as plt
from pylinac.core.image_generator import AS1200Image
from pylinac.core.image_generator.layers import FilteredFieldLayer, GaussianFilterLayer

as1200 = AS1200Image()
height = 350
width = 4
offsets = range(-100, 100, 20)
for offset in offsets:
    as1200.add_layer(FilteredFieldLayer((height, width), cax_offset_mm=(0, offset)))
as1200.add_layer(GaussianFilterLayer())
plt.imshow(as1200.image)
plt.show()