def _init_from_Vrepresentation(self, vertices, rays, lines, minimize=True, verbose=False):
"""
Construct polyhedron from V-representation data.
INPUT:
- ``vertices`` -- list of point. Each point can be specified
as any iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
- ``rays`` -- list of rays. Each ray can be specified as any
iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
- ``lines`` -- list of lines. Each line can be specified as
any iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
- ``verbose`` -- boolean (default: ``False``). Whether to print
verbose output for debugging purposes.
EXAMPLES::
sage: p = Polyhedron(backend='ppl')
sage: from sage.geometry.polyhedron.backend_ppl import Polyhedron_ppl
sage: Polyhedron_ppl._init_from_Vrepresentation(p, [], [], [])
"""
gs = Generator_System()
if vertices is None: vertices = []
for v in vertices:
d = LCM_list([denominator(v_i) for v_i in v])
if d.is_one():
gs.insert(point(Linear_Expression(v, 0)))
else:
dv = [ d*v_i for v_i in v ]
gs.insert(point(Linear_Expression(dv, 0), d))
if rays is None: rays = []
for r in rays:
d = LCM_list([denominator(r_i) for r_i in r])
if d.is_one():
gs.insert(ray(Linear_Expression(r, 0)))
else:
dr = [ d*r_i for r_i in r ]
gs.insert(ray(Linear_Expression(dr, 0)))
if lines is None: lines = []
for l in lines:
d = LCM_list([denominator(l_i) for l_i in l])
if d.is_one():
gs.insert(line(Linear_Expression(l, 0)))
else:
dl = [ d*l_i for l_i in l ]
gs.insert(line(Linear_Expression(dl, 0)))
if gs.empty():
self._ppl_polyhedron = C_Polyhedron(self.ambient_dim(), 'empty')
else:
self._ppl_polyhedron = C_Polyhedron(gs)
self._init_Vrepresentation_from_ppl(minimize)
self._init_Hrepresentation_from_ppl(minimize)
def _init_from_Vrepresentation(self, vertices, rays, lines, minimize=True):
"""
Construct polyhedron from V-representation data.
INPUT:
- ``vertices`` -- list of point. Each point can be specified
as any iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
- ``rays`` -- list of rays. Each ray can be specified as any
iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
- ``lines`` -- list of lines. Each line can be specified as
any iterable container of
:meth:`~sage.geometry.polyhedron.base.base_ring` elements.
EXAMPLES::
sage: p = Polyhedron(backend='ppl')
sage: from sage.geometry.polyhedron.backend_ppl import Polyhedron_ppl
sage: Polyhedron_ppl._init_from_Vrepresentation(p, [], [], [])
"""
gs = Generator_System()
if vertices is None: vertices = []
for v in vertices:
d = LCM_list([denominator(v_i) for v_i in v])
if d.is_one():
gs.insert(point(Linear_Expression(v, 0)))
else:
dv = [d * v_i for v_i in v]
gs.insert(point(Linear_Expression(dv, 0), d))
if rays is None: rays = []
for r in rays:
d = LCM_list([denominator(r_i) for r_i in r])
if d.is_one():
gs.insert(ray(Linear_Expression(r, 0)))
else:
dr = [d * r_i for r_i in r]
gs.insert(ray(Linear_Expression(dr, 0)))
if lines is None: lines = []
for l in lines:
d = LCM_list([denominator(l_i) for l_i in l])
if d.is_one():
gs.insert(line(Linear_Expression(l, 0)))
else:
dl = [d * l_i for l_i in l]
gs.insert(line(Linear_Expression(dl, 0)))
if gs.empty():
self._ppl_polyhedron = C_Polyhedron(self.ambient_dim(), 'empty')
else:
self._ppl_polyhedron = C_Polyhedron(gs)
self._init_Vrepresentation_from_ppl(minimize)
self._init_Hrepresentation_from_ppl(minimize)
def LatticePolytope_PPL(*args):
"""
Construct a new instance of the PPL-based lattice polytope class.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((0,0),(1,0),(0,1))
A 2-dimensional lattice polytope in ZZ^2 with 3 vertices
sage: from sage.libs.ppl import point, Generator_System, C_Polyhedron, Linear_Expression, Variable
sage: p = point(Linear_Expression([2,3],0)); p
point(2/1, 3/1)
sage: LatticePolytope_PPL(p)
A 0-dimensional lattice polytope in ZZ^2 with 1 vertex
sage: P = C_Polyhedron(Generator_System(p)); P
A 0-dimensional polyhedron in QQ^2 defined as the convex hull of 1 point
sage: LatticePolytope_PPL(P)
A 0-dimensional lattice polytope in ZZ^2 with 1 vertex
A ``TypeError`` is raised if the arguments do not specify a lattice polytope::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((0,0),(1/2,1))
Traceback (most recent call last):
...
TypeError: no conversion of this rational to integer
sage: from sage.libs.ppl import point, Generator_System, C_Polyhedron, Linear_Expression, Variable
sage: p = point(Linear_Expression([2,3],0), 5); p
point(2/5, 3/5)
sage: LatticePolytope_PPL(p)
Traceback (most recent call last):
...
TypeError: generator is not a lattice polytope generator
sage: P = C_Polyhedron(Generator_System(p)); P
A 0-dimensional polyhedron in QQ^2 defined as the convex hull of 1 point
sage: LatticePolytope_PPL(P)
Traceback (most recent call last):
...
TypeError: polyhedron has non-integral generators
"""
polytope_class = LatticePolytope_PPL_class
if len(args)==1 and isinstance(args[0], C_Polyhedron):
polyhedron = args[0]
polytope_class = _class_for_LatticePolytope(polyhedron.space_dimension())
if not all(p.is_point() and p.divisor().is_one() for p in polyhedron.generators()):
raise TypeError('polyhedron has non-integral generators')
return polytope_class(polyhedron)
if len(args)==1 \
and isinstance(args[0], (list, tuple)) \
and isinstance(args[0][0], (list,tuple)):
vertices = args[0]
else:
vertices = args
gs = Generator_System()
for v in vertices:
if isinstance(v, Generator):
if (not v.is_point()) or (not v.divisor().is_one()):
raise TypeError('generator is not a lattice polytope generator')
gs.insert(v)
else:
gs.insert(point(Linear_Expression(v, 0)))
if not gs.empty():
dim = next(Generator_System_iterator(gs)).space_dimension()
polytope_class = _class_for_LatticePolytope(dim)
return polytope_class(gs)
def LatticePolytope_PPL(*args):
"""
Construct a new instance of the PPL-based lattice polytope class.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((0,0),(1,0),(0,1))
A 2-dimensional lattice polytope in ZZ^2 with 3 vertices
sage: from sage.libs.ppl import point, Generator_System, C_Polyhedron, Linear_Expression, Variable
sage: p = point(Linear_Expression([2,3],0)); p
point(2/1, 3/1)
sage: LatticePolytope_PPL(p)
A 0-dimensional lattice polytope in ZZ^2 with 1 vertex
sage: P = C_Polyhedron(Generator_System(p)); P
A 0-dimensional polyhedron in QQ^2 defined as the convex hull of 1 point
sage: LatticePolytope_PPL(P)
A 0-dimensional lattice polytope in ZZ^2 with 1 vertex
A ``TypeError`` is raised if the arguments do not specify a lattice polytope::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((0,0),(1/2,1))
Traceback (most recent call last):
...
TypeError: no conversion of this rational to integer
sage: from sage.libs.ppl import point, Generator_System, C_Polyhedron, Linear_Expression, Variable
sage: p = point(Linear_Expression([2,3],0), 5); p
point(2/5, 3/5)
sage: LatticePolytope_PPL(p)
Traceback (most recent call last):
...
TypeError: generator is not a lattice polytope generator
sage: P = C_Polyhedron(Generator_System(p)); P
A 0-dimensional polyhedron in QQ^2 defined as the convex hull of 1 point
sage: LatticePolytope_PPL(P)
Traceback (most recent call last):
...
TypeError: polyhedron has non-integral generators
"""
polytope_class = LatticePolytope_PPL_class
if len(args)==1 and isinstance(args[0], C_Polyhedron):
polyhedron = args[0]
polytope_class = _class_for_LatticePolytope(polyhedron.space_dimension())
if not all(p.is_point() and p.divisor().is_one() for p in polyhedron.generators()):
raise TypeError('polyhedron has non-integral generators')
return polytope_class(polyhedron)
if len(args)==1 \
and isinstance(args[0], (list, tuple)) \
and isinstance(args[0][0], (list,tuple)):
vertices = args[0]
else:
vertices = args
gs = Generator_System()
for v in vertices:
if isinstance(v, Generator):
if (not v.is_point()) or (not v.divisor().is_one()):
raise TypeError('generator is not a lattice polytope generator')
gs.insert(v)
else:
gs.insert(point(Linear_Expression(v, 0)))
if not gs.empty():
dim = Generator_System_iterator(gs).next().space_dimension()
polytope_class = _class_for_LatticePolytope(dim)
return polytope_class(gs)
