Source Code for Module geometry.manifolds.tangent_bundle

 1  from . import DifferentiableManifold, contract 
 2   
 3   
 4 -class TangentBundle(DifferentiableManifold): 
 5      ''' This class represents the tangent bundle of a generic manifold 
 6          using a tuple (base, vel) where vel is tangent at base. 
 7           
 8          (MatrixLieGroup has different representation) 
 9      ''' 
10   
11      # TODO: create tests for all of this 
12   
13 -    def __init__(self, base_manifold): 
14          self.base = base_manifold 
15          dimension = 2 * base_manifold.get_dimension() 
16          DifferentiableManifold.__init__(self, dimension=dimension) 
17   
18 -    def __str__(self): 
19          return "T%s" % self.base 
20   
21 -    def belongs(self, x): 
22          return self.base.belongs_ts(x) 
23   
24 -    def belongs_ts(self, bv): 
25          # XXX: can we make it recursive? 
26          raise ValueError('Not supported') 
27   
28 -    def project_ts(self, bv): # TODO: test 
29          # XXX: can we make it recursive? 
30          raise ValueError('Not supported') 
31   
32      @contract(a='belongs', b='belongs', returns='>=0') 
33 -    def distance(self, a, b): 
34          # TODO: make checks for this 
35          # TODO: implement 
36          raise ValueError('Not supported') 
37   
38      @contract(base='belongs', p='belongs', returns='belongs_ts') 
39 -    def logmap(self, base, p): 
40          raise ValueError('Not supported') 
41   
42      @contract(bv='belongs_ts', returns='belongs') 
43 -    def expmap(self, bv): 
44          raise ValueError('Not supported') 
45   
46      @contract(returns='list(belongs)') 
47 -    def interesting_points(self): 
48          # TODO: write this 
49          return [] 
50   
51      @contract(a='belongs') 
52 -    def friendly(self, a): 
53          '''  
54              Returns a friendly description string for a point on the manifold.  
55          ''' 
56          return "%s" % a 
57