[Matplotlib-users] how to plot a sphere and two more curves, and the aspect ratio to be preserved

[Emilia P. <emi...@gm...>]

Dear all,


I want to visualize the image through the stereographic projection (that
maps
the extended complex plane to the unit sphere), of a circle and a line from
the plane.

I imported:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure()
ax = fig.add_subplot(111,  projection='3d')

If I plot only the  the sphere and  a circle in the plane xoy and set:

ax.set_aspect('equal')

all is OK, but inserting one more plot for the image of the circle onto the
sphere,
the aspect is changed and the sphere is displayed as an ellipsoid.

My question is:  how could I lock the aspect in order to keep the geometry
of the sphere?

Thanks,

Em