def create_unit_sphere(recursion_level=2):
""" Creates a unit sphere by subdividing a unit octahedron.
Starts with a unit octahedron and subdivides the faces, projecting the
resulting points onto the surface of a unit sphere.
Parameters
------------
recursion_level : int
Level of subdivision, recursion_level=1 will return an octahedron,
anything bigger will return a more subdivided sphere. The sphere will
have $4^recursion_level+2$ vertices.
Returns
---------
Sphere :
The unit sphere.
See Also
----------
create_unit_hemisphere, Sphere
"""
if recursion_level > 7 or recursion_level < 1:
raise ValueError("recursion_level must be between 1 and 7")
return unit_octahedron.subdivide(recursion_level - 1)
def test_sphere_subdivide():
sphere1 = unit_octahedron.subdivide(4)
sphere2 = Sphere(xyz=sphere1.vertices)
nt.assert_equal(sphere1.faces.shape, sphere2.faces.shape)
nt.assert_equal(array_to_set(sphere1.faces), array_to_set(sphere2.faces))
sphere1 = unit_icosahedron.subdivide(4)
sphere2 = Sphere(xyz=sphere1.vertices)
nt.assert_equal(sphere1.faces.shape, sphere2.faces.shape)
nt.assert_equal(array_to_set(sphere1.faces), array_to_set(sphere2.faces))
def test_sphere_subdivide():
sphere1 = unit_octahedron.subdivide(4)
sphere2 = Sphere(xyz=sphere1.vertices)
nt.assert_equal(sphere1.faces.shape, sphere2.faces.shape)
nt.assert_equal(array_to_set(sphere1.faces), array_to_set(sphere2.faces))
sphere1 = unit_icosahedron.subdivide(4)
sphere2 = Sphere(xyz=sphere1.vertices)
nt.assert_equal(sphere1.faces.shape, sphere2.faces.shape)
nt.assert_equal(array_to_set(sphere1.faces), array_to_set(sphere2.faces))
def test_sphere_find_closest():
sphere1 = unit_octahedron.subdivide(4)
for ii in range(sphere1.vertices.shape[0]):
nt.assert_equal(sphere1.find_closest(sphere1.vertices[ii]), ii)
def test_sphere_find_closest():
sphere1 = unit_octahedron.subdivide(4)
for ii in range(sphere1.vertices.shape[0]):
nt.assert_equal(sphere1.find_closest(sphere1.vertices[ii]), ii)
