def _link_exterior(self,
with_hyperbolic_structure=True,
remove_finite_vertices=True):
"""
The exterior or complement of the link L, that is, S^3 minus L.
>>> K = Link('4_1')
>>> M = K.exterior()
>>> M.volume() # doctest: +NUMERIC6
2.02988321
By default, SnapPy will try to find a hyperbolic structure on the
exterior. To return a Triangulation instead of a Manifold, set the
flag with_hyperbolic_structure to False. If you want to get the
intermediate triangulation with extra vertices above and below the
projection plane, set the flag remove_finite_vertices to False.
>>> M = K.exterior(False, False)
>>> (M.num_cusps(), M._num_fake_cusps())
(1, 2)
"""
M = Triangulation('empty')
M._get_from_link_data(self.KLPProjection(), remove_finite_vertices)
if with_hyperbolic_structure:
M = M.with_hyperbolic_structure()
dt = DTcodec(*self.DT_code(flips=True))
M._set_DTcode(dt)
if self.name:
M.set_name(self.name)
return M
def high_precision(self):
"""
Return a high precision version of this manifold.
>>> M = Manifold('m004')
>>> type(M.high_precision())
<class 'snappy.ManifoldHP'>
"""
HP = ManifoldHP('empty')
HP._from_string(self._to_string(), initialize_structure=False)
fillings = [self.cusp_info(n).filling for n in range(self.num_cusps())]
filled = self._get_tetrahedra_shapes('filled')
complete = self._get_tetrahedra_shapes('complete')
HP.set_tetrahedra_shapes(filled, complete, fillings)
HP._polish_hyperbolic_structures()
HP.set_name(self.name())
DT = self.DT_code()
if DT:
HP._set_DTcode(DTcodec(DT))
return HP
def low_precision(self):
"""
Return a low precision version of this high precision manifold.
>>> M = ManifoldHP('m004')
>>> type(M.low_precision())
<class 'snappy.Manifold'>
"""
LP = Manifold('empty')
LP._from_string(self._to_string(), initialize_structure=False)
fillings = [self.cusp_info(n).filling for n in range(self.num_cusps())]
filled = [complex(z) for z in self._get_tetrahedra_shapes('filled')]
complete = [
complex(z) for z in self._get_tetrahedra_shapes('complete')
]
LP.set_tetrahedra_shapes(filled, complete, fillings)
LP._polish_hyperbolic_structures()
LP.set_name(self.name())
DT = self.DT_code(flips=True)
if DT:
LP._set_DTcode(DTcodec(*DT))
return LP