px = np.random.rand(10)
py = np.random.rand(10)
offsets = np.ma.column_stack([px, py])
#%% 1
fig, ax = plt.subplots()
reduction = 50
c = Path.unit_circle()
c = c.transformed(Affine2D().scale(0.5 * reduction))
collection = PathCollection(
(c,), offsets=offsets,
transOffset = ax.transData,
edgecolor='black',
facecolor=(0, 0, 0, .0125),
linewidth=1
)
collection.set_transform(IdentityTransform())
ax.add_collection( collection )
#%% 2
collection.set_path_effects([withStroke(linewidth=5, foreground='r')])
collection.set_path_effects([])
collection.get_path_effects()
