Source Code for Module geometry.spheres_embedding

 1  from . import contract, np 
 2   
 3   
 4  @contract(returns='S2', a='S1') 
 5 -def S2_from_S1(a): 
 6      return np.array([a[0], a[1], 0]) 
 7   
 8   
 9  @contract(returns='S1', b='S2') 
10 -def S1_project_from_S2(b): 
11      if np.abs(b[2]) == 1: 
12          return np.array([1, 0]) 
13      theta = np.arctan2(b[1], b[0]) 
14      return np.array([np.cos(theta), np.sin(theta)]) 
15   
16   
17  @contract(returns='S1', b='R2') 
18 -def S1_project_from_R2(b): 
19      norm = np.linalg.norm(b) 
20      atol = 1e-8 # XXX 
21      if norm <= atol: 
22          return np.array([1, 0]) 
23      return b / norm 
24   
25   
26  @contract(returns='S2', b='R3') 
27 -def S2_project_from_R3(b): 
28      norm = np.linalg.norm(b) 
29      atol = 1e-8 # XXX 
30      if norm <= atol: 
31          return np.array([1, 0, 0]) 
32      return b / norm 
33