diff --git a/src/doc/en/reference/references/index.rst b/src/doc/en/reference/references/index.rst index 4c9c2fd1ab4..018c993a57d 100644 --- a/src/doc/en/reference/references/index.rst +++ b/src/doc/en/reference/references/index.rst @@ -1645,9 +1645,12 @@ REFERENCES: constrained optimization. ACM Transactions on Mathematical Software, Vol 23, Num. 4, pp.550--560, 1997. -.. [Zie1998] G. Ziegler. *Shelling polyhedral 3-balls and +.. [Zie1998] G. M. Ziegler. *Shelling polyhedral 3-balls and 4-polytopes*. Discrete Comput. Geom. 19 (1998), 159-174. +.. [Zie2007] G. M. Ziegler. *Lectures on polytopes*, Volume + 152 of Graduate Texts in Mathematics, 7th printing of 1st edition, Springer, 2007. + .. [Zor2008] \A. Zorich "Explicit Jenkins-Strebel representatives of all strata of Abelian and quadratic differentials", Journal of Modern Dynamics, vol. 2, no 1, 139-185 (2008) diff --git a/src/sage/geometry/polyhedron/base.py b/src/sage/geometry/polyhedron/base.py index 5f7421b8ba4..5e68649aa2a 100644 --- a/src/sage/geometry/polyhedron/base.py +++ b/src/sage/geometry/polyhedron/base.py @@ -2268,6 +2268,48 @@ def gale_transform(self): A_ker = A.right_kernel() return A_ker.basis_matrix().transpose().rows() + @cached_method + def normal_fan(self): + r""" + Return the normal fan of a compact full-dimensional rational polyhedron. + + OUTPUT: + + A complete fan of the ambient space as a + :class:`~sage.geometry.fan.RationalPolyhedralFan`. + + .. SEEALSO:: + + :meth:`~sage.geometry.polyhedron.base.face_fan`. + + REFERENCES: + + For more information, see Chapter 7 of [Zie2007]_. + """ + + return NormalFan(self) + + @cached_method + def face_fan(self): + r""" + Return the face fan of a compact full-dimensional rational polyhedron. + + OUTPUT: + + A complete fan of the ambient space as a + :class:`~sage.geometry.fan.RationalPolyhedralFan`. + + .. SEEALSO:: + + :meth:`~sage.geometry.polyhedron.base.normal_fan`. + + REFERENCES: + + For more information, see Chapter 7 of [Zie2007]_. + """ + + return FaceFan(self) + def triangulate(self, engine='auto', connected=True, fine=False, regular=None, star=None): r""" Returns a triangulation of the polytope.