def as_embedded_number_field_elements(algs):
# number_field_elements_from_algebraics() now takes an embedded=...
# argument, but doesn't yet support all cases we need
nf, elts, emb = number_field_elements_from_algebraics(algs)
if nf is not QQ:
nf = NumberField(nf.polynomial(), nf.variable_name(),
embedding=emb(nf.gen()))
elts = [elt.polynomial()(nf.gen()) for elt in elts]
nf, hom = good_number_field(nf)
elts = [hom(elt) for elt in elts]
# assert [QQbar.coerce(elt) == alg for alg, elt in zip(algs, elts)]
return nf, elts
def as_embedded_number_field_elements(algs):
try:
nf, elts, _ = number_field_elements_from_algebraics(algs, embedded=True)
except NotImplementedError: # compatibility with Sage <= 9.3
nf, elts, emb = number_field_elements_from_algebraics(algs)
if nf is not QQ:
nf = NumberField(nf.polynomial(), nf.variable_name(),
embedding=emb(nf.gen()))
elts = [elt.polynomial()(nf.gen()) for elt in elts]
nf, hom = good_number_field(nf)
elts = [hom(elt) for elt in elts]
assert [QQbar.coerce(elt) == alg for alg, elt in zip(algs, elts)]
return nf, elts
def platonic_icosahedron():
r"""Produce a triple consisting of a polyhedral version of the platonic icosahedron,
the associated cone surface, and a ConeSurfaceToPolyhedronMap from the surface
to the polyhedron.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import platonic_icosahedron
sage: polyhedron,surface,surface_to_polyhedron = platonic_icosahedron()
sage: TestSuite(surface).run()
r"""
vertices=[]
phi=AA(1+sqrt(5))/2
F=NumberField(phi.minpoly(),"phi",embedding=phi)
phi=F.gen()
for i in xrange(3):
for s1 in xrange(-1,3,2):
for s2 in xrange(-1,3,2):
p=3*[None]
p[i]=s1*phi
p[(i+1)%3]=s2
p[(i+2)%3]=0
vertices.append(vector(F,p))
p=Polyhedron(vertices=vertices)
s,m = polyhedron_to_cone_surface(p)
return p,s,m
def platonic_dodecahedron():
r"""Produce a triple consisting of a polyhedral version of the platonic dodecahedron,
the associated cone surface, and a ConeSurfaceToPolyhedronMap from the surface
to the polyhedron.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import platonic_dodecahedron
sage: polyhedron,surface,surface_to_polyhedron = platonic_dodecahedron()
sage: TestSuite(surface).run()
r"""
vertices=[]
phi=AA(1+sqrt(5))/2
F=NumberField(phi.minpoly(),"phi",embedding=phi)
phi=F.gen()
for x in xrange(-1,3,2):
for y in xrange(-1,3,2):
for z in xrange(-1,3,2):
vertices.append(vector(F,(x,y,z)))
for x in xrange(-1,3,2):
for y in xrange(-1,3,2):
vertices.append(vector(F,(0,x*phi,y/phi)))
vertices.append(vector(F,(y/phi,0,x*phi)))
vertices.append(vector(F,(x*phi,y/phi,0)))
scale=AA(2/sqrt(1+(phi-1)**2+(1/phi-1)**2))
p=Polyhedron(vertices=vertices)
s,m = polyhedron_to_cone_surface(p,scaling_factor=scale)
return p,s,m
def number_field_elements_from_algebraics(elts, name='a'):
r"""
The native Sage function ``number_field_elements_from_algebraics`` currently
returns number field *without* embedding. This function return field with
embedding!
EXAMPLES::
sage: from flatsurf.geometry.polygon import number_field_elements_from_algebraics
sage: z = QQbar.zeta(5)
sage: c = z.real()
sage: s = z.imag()
sage: number_field_elements_from_algebraics((c,s))
(Number Field in a with defining polynomial y^4 - 5*y^2 + 5,
[1/2*a^2 - 3/2, 1/2*a])
"""
from sage.rings.qqbar import number_field_elements_from_algebraics
from sage.rings.number_field.number_field import NumberField
field,elts,phi = number_field_elements_from_algebraics(elts, minimal=True)
polys = [x.polynomial() for x in elts]
K = NumberField(field.polynomial(), name, embedding=AA(phi(field.gen())))
gen = K.gen()
return K, [x.polynomial()(gen) for x in elts]
def platonic_icosahedron():
r"""Produce a triple consisting of a polyhedral version of the platonic icosahedron,
the associated cone surface, and a ConeSurfaceToPolyhedronMap from the surface
to the polyhedron.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import platonic_icosahedron
sage: polyhedron,surface,surface_to_polyhedron = platonic_icosahedron()
sage: TestSuite(surface).run()
r"""
vertices = []
phi = AA(1 + sqrt(5)) / 2
F = NumberField(phi.minpoly(), "phi", embedding=phi)
phi = F.gen()
for i in range(3):
for s1 in range(-1, 3, 2):
for s2 in range(-1, 3, 2):
p = 3 * [None]
p[i] = s1 * phi
p[(i + 1) % 3] = s2
p[(i + 2) % 3] = 0
vertices.append(vector(F, p))
p = Polyhedron(vertices=vertices)
s, m = polyhedron_to_cone_surface(p)
return p, s, m
def platonic_dodecahedron():
r"""Produce a triple consisting of a polyhedral version of the platonic dodecahedron,
the associated cone surface, and a ConeSurfaceToPolyhedronMap from the surface
to the polyhedron.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import platonic_dodecahedron
sage: polyhedron,surface,surface_to_polyhedron = platonic_dodecahedron()
sage: TestSuite(surface).run()
r"""
vertices = []
phi = AA(1 + sqrt(5)) / 2
F = NumberField(phi.minpoly(), "phi", embedding=phi)
phi = F.gen()
for x in range(-1, 3, 2):
for y in range(-1, 3, 2):
for z in range(-1, 3, 2):
vertices.append(vector(F, (x, y, z)))
for x in range(-1, 3, 2):
for y in range(-1, 3, 2):
vertices.append(vector(F, (0, x * phi, y / phi)))
vertices.append(vector(F, (y / phi, 0, x * phi)))
vertices.append(vector(F, (x * phi, y / phi, 0)))
scale = AA(2 / sqrt(1 + (phi - 1)**2 + (1 / phi - 1)**2))
p = Polyhedron(vertices=vertices)
s, m = polyhedron_to_cone_surface(p, scaling_factor=scale)
return p, s, m
def _number_field_from_algebraics(self):
r"""
Given a projective point defined over ``QQbar``, return the same point, but defined
over a number field.
This is only implemented for points of projective space.
OUTPUT: scheme point
EXAMPLES::
sage: R.<x> = PolynomialRing(QQ)
sage: P.<x,y> = ProjectiveSpace(QQbar,1)
sage: Q = P([-1/2*QQbar(sqrt(2)) + QQbar(I), 1])
sage: S = Q._number_field_from_algebraics(); S
(1/2*a^3 + a^2 - 1/2*a : 1)
sage: S.codomain()
Projective Space of dimension 1 over Number Field in a with defining polynomial y^4 + 1 with a = 0.7071067811865475? + 0.7071067811865475?*I
The following was fixed in :trac:`23808`::
sage: R.<x> = PolynomialRing(QQ)
sage: P.<x,y> = ProjectiveSpace(QQbar,1)
sage: Q = P([-1/2*QQbar(sqrt(2)) + QQbar(I), 1]);Q
(-0.7071067811865475? + 1*I : 1)
sage: S = Q._number_field_from_algebraics(); S
(1/2*a^3 + a^2 - 1/2*a : 1)
sage: T = S.change_ring(QQbar) # Used to fail
sage: T
(-0.7071067811865475? + 1.000000000000000?*I : 1)
sage: Q[0] == T[0]
True
"""
from sage.schemes.projective.projective_space import is_ProjectiveSpace
if not is_ProjectiveSpace(self.codomain()):
raise NotImplementedError("not implemented for subschemes")
# Trac #23808: Keep the embedding info associated with the number field K
# used below, instead of in the separate embedding map phi which is
# forgotten.
K_pre, P, phi = number_field_elements_from_algebraics(list(self))
if K_pre is QQ:
K = QQ
else:
from sage.rings.number_field.number_field import NumberField
K = NumberField(K_pre.polynomial(),
embedding=phi(K_pre.gen()),
name='a')
psi = K_pre.hom([K.gen()], K) # Identification of K_pre with K
P = [psi(p) for p in P] # The elements of P were elements of K_pre
from sage.schemes.projective.projective_space import ProjectiveSpace
PS = ProjectiveSpace(K, self.codomain().dimension_relative(), 'z')
return PS(P)
def as_embedded_number_field_element(alg):
from sage.rings.number_field.number_field import NumberField
nf, elt, emb = alg.as_number_field_element()
if nf is QQ:
res = elt
else:
embnf = NumberField(nf.polynomial(),
nf.variable_name(),
embedding=emb(nf.gen()))
res = elt.polynomial()(embnf.gen())
# assert QQbar.coerce(res) == alg
return res
def __init__(self,lambda_squared=None, field=None):
if lambda_squared==None:
from sage.rings.number_field.number_field import NumberField
from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
R=PolynomialRing(ZZ,'x')
x = R.gen()
from sage.rings.qqbar import AA
field=NumberField(x**3-ZZ(5)*x**2+ZZ(4)*x-ZZ(1), 'r', embedding=AA(ZZ(4)))
self._l=field.gen()
else:
if field is None:
self._l=lambda_squared
field=lambda_squared.parent()
else:
self._l=field(lambda_squared)
Surface.__init__(self,field, ZZ.zero(), finite=False)
def polyhedron_to_cone_surface(polyhedron, use_AA=False, scaling_factor=ZZ(1)):
r"""Construct the Euclidean Cone Surface associated to the surface of a polyhedron and a map
from the cone surface to the polyhedron.
INPUT:
- ``polyhedron`` -- A 3-dimensional polyhedron, which should be define over something that coerces into AA
- ``use_AA`` -- If True, the surface returned will be defined over AA. If false, the algorithm will find the smallest NumberField and write the field there.
- ``scaling_factor`` -- The surface returned will have a metric scaled by multiplication by this factor (compared with the original polyhendron). This can be used to produce a surface defined over a smaller NumberField.
OUTPUT:
A pair consisting of a ConeSurface and a ConeSurfaceToPolyhedronMap.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import *
sage: vertices=[]
sage: for i in xrange(3):
....: temp=vector([1 if k==i else 0 for k in xrange(3)])
....: for j in xrange(-1,3,2):
....: vertices.append(j*temp)
sage: octahedron=Polyhedron(vertices=vertices)
sage: surface,surface_to_octahedron = \
....: polyhedron_to_cone_surface(octahedron,scaling_factor=AA(1/sqrt(2)))
sage: TestSuite(surface).run()
sage: TestSuite(surface_to_octahedron).run(skip="_test_pickling")
sage: surface.num_polygons()
8
sage: surface.base_ring()
Number Field in a with defining polynomial y^2 - 3
sage: sqrt3=surface.base_ring().gen()
sage: tangent_bundle=surface.tangent_bundle()
sage: v=tangent_bundle(0,(0,0),(sqrt3,2))
sage: traj=v.straight_line_trajectory()
sage: traj.flow(10)
sage: traj.is_saddle_connection()
True
sage: traj.combinatorial_length()
8
sage: surface_to_octahedron(traj)
[(-1, 0, 0),
(0.?e-18, -0.8000000000000000?, -0.2000000000000000?),
(0.2500000000000000?, -0.750000000000000?, 0.?e-18),
(0.4000000000000000?, 0.?e-19, 0.6000000000000000?),
(0.?e-19, 0.500000000000000?, 0.500000000000000?),
(-2/5, 3/5, 0),
(-0.2500000000000000?, 0.?e-18, -0.750000000000000?),
(0.?e-18, -0.2000000000000000?, -0.8000000000000000?),
(1, 0, 0)]
sage: surface_to_octahedron(traj.segment(0))
((-1, 0, 0), (0.?e-18, -0.8000000000000000?, -0.2000000000000000?))
sage: surface_to_octahedron(traj.segment(0).start())
((-1, 0, 0), (2.886751345948129?, -2.309401076758503?, -0.5773502691896258?))
sage: # octahedron.plot(wireframe=None,frame=False)+line3d(surface_to_octahedron(traj),radius=0.01)
"""
assert polyhedron.dim()==3
c=polyhedron.center()
vertices=polyhedron.vertices()
vertex_order={}
for i,v in enumerate(vertices):
vertex_order[v]=i
faces=polyhedron.faces(2)
face_order={}
face_edges=[]
face_vertices=[]
face_map_data=[]
for i,f in enumerate(faces):
face_order[f]=i
edges=f.as_polyhedron().faces(1)
face_edges_temp = set()
for edge in edges:
edge_temp=set()
for vertex in edge.vertices():
v=vertex.vector()
v.set_immutable()
edge_temp.add(v)
face_edges_temp.add(frozenset(edge_temp))
last_edge = next(iter(face_edges_temp))
v = next(iter(last_edge))
face_vertices_temp=[v]
for j in xrange(len(face_edges_temp)-1):
for edge in face_edges_temp:
if v in edge and edge!=last_edge:
# bingo
last_edge=edge
for vv in edge:
if vv!=v:
v=vv
face_vertices_temp.append(vv)
break
break
v0=face_vertices_temp[0]
v1=face_vertices_temp[1]
v2=face_vertices_temp[2]
n=(v1-v0).cross_product(v2-v0)
if (v0-c).dot_product(n)<0:
n=-n
face_vertices_temp.reverse()
v0=face_vertices_temp[0]
v1=face_vertices_temp[1]
v2=face_vertices_temp[2]
face_vertices.append(face_vertices_temp)
n=n/AA(n.norm())
w=v1-v0
w=w/AA(w.norm())
m=1/scaling_factor*matrix(AA,[w,n.cross_product(w),n]).transpose()
mi=~m
mis=mi.submatrix(0,0,2,3)
face_map_data.append((
v0, # translation to bring origin in plane to v0
m.submatrix(0,0,3,2),
-mis*v0,
mis
))
it=iter(face_vertices_temp)
v_last=next(it)
face_edge_dict={}
j=0
for v in it:
edge=frozenset([v_last,v])
face_edge_dict[edge]=j
j+=1
v_last=v
v=next(iter(face_vertices_temp))
edge=frozenset([v_last,v])
face_edge_dict[edge]=j
face_edges.append(face_edge_dict)
gluings={}
for p1,face_edge_dict1 in enumerate(face_edges):
for edge, e1 in face_edge_dict1.items():
found=False
for p2, face_edge_dict2 in enumerate(face_edges):
if p1!=p2 and edge in face_edge_dict2:
e2=face_edge_dict2[edge]
gluings[(p1,e1)]=(p2,e2)
found=True
break
if not found:
print(p1)
print(e1)
print(edge)
raise RuntimeError("Failed to find glued edge")
polygon_vertices_AA=[]
for p,vs in enumerate(face_vertices):
trans=face_map_data[p][2]
m=face_map_data[p][3]
polygon_vertices_AA.append([trans+m*v for v in vs])
if use_AA==True:
Polys=Polygons(AA)
polygons=[]
for vs in polygon_vertices_AA:
polygons.append(Polys(vertices=vs))
S=ConeSurface(surface_list_from_polygons_and_gluings(polygons,gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
else:
elts=[]
for vs in polygon_vertices_AA:
for v in vs:
elts.append(v[0])
elts.append(v[1])
# Find the best number field:
field,elts2,hom = number_field_elements_from_algebraics(elts,minimal=True)
if field==QQ:
# Defined over the rationals!
polygon_vertices_field2=[]
j=0
for vs in polygon_vertices_AA:
vs2=[]
for v in vs:
vs2.append(vector(field,[elts2[j],elts2[j+1]]))
j=j+2
polygon_vertices_field2.append(vs2)
Polys=Polygons(field)
polygons=[]
for vs in polygon_vertices_field2:
polygons.append(Polys(vertices=vs))
S=ConeSurface(surface_list_from_polygons_and_gluings(polygons,gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
else:
# Unfortunately field doesn't come with an real embedding (which is given by hom!)
# So, we make a copy of the field, and add the embedding.
field2=NumberField(field.polynomial(),name="a",embedding=hom(field.gen()))
# The following converts from field to field2:
hom2=field.hom(im_gens=[field2.gen()])
polygon_vertices_field2=[]
j=0
for vs in polygon_vertices_AA:
vs2=[]
for v in vs:
vs2.append(vector(field2,[hom2(elts2[j]),hom2(elts2[j+1])]))
j=j+2
polygon_vertices_field2.append(vs2)
Polys=Polygons(field2)
polygons=[]
for vs in polygon_vertices_field2:
polygons.append(Polys(vertices=vs))
S=ConeSurface(surface_list_from_polygons_and_gluings(polygons,gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
class EInfinitySurface(Surface):
r"""
The surface based on the $E_\infinity$ graph.
The biparite graph is shown below, with edges numbered:
0 1 2 -2 3 -3 4 -4
*---o---*---o---*---o---*---o---*...
|
|-1
o
Here, black vertices are colored *, and white o.
Black nodes represent vertical cylinders and white nodes
represent horizontal cylinders.
"""
def __init__(self,lambda_squared=None, field=None):
TranslationSurface_generic.__init__(self)
if lambda_squared==None:
from sage.rings.number_field.number_field import NumberField
from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing
R=PolynomialRing(ZZ,'x')
x = R.gen()
from sage.rings.qqbar import AA
self._field=NumberField(x**3-ZZ(5)*x**2+ZZ(4)*x-ZZ(1), 'r', embedding=AA(ZZ(4)))
self._l=self._field.gen()
else:
if field is None:
self._l=lambda_squared
self._field=lambda_squared.parent()
else:
self._field=field
self._l=field(lambda_squared)
Surface.__init__(self)
def _repr_(self):
r"""
String representation.
"""
return "The E-infinity surface"
def base_ring(self):
r"""
Return the rational field.
"""
return self._field
def base_label(self):
return ZZ.zero()
@cached_method
def get_white(self,n):
r"""Get the weight of the white endpoint of edge n."""
l=self._l
if n==0 or n==1:
return l
if n==-1:
return l-1
if n==2:
return 1-3*l+l**2
if n>2:
x=self.get_white(n-1)
y=self.get_black(n)
return l*y-x
return self.get_white(-n)
@cached_method
def get_black(self,n):
r"""Get the weight of the black endpoint of edge n."""
l=self._l
if n==0:
return self._field(1)
if n==1 or n==-1 or n==2:
return l-1
if n>2:
x=self.get_black(n-1)
y=self.get_white(n-1)
return y-x
return self.get_black(1-n)
def polygon(self, lab):
r"""
Return the polygon labeled by ``lab``.
"""
if lab not in self.polygon_labels():
raise ValueError("lab (=%s) not a valid label"%lab)
from flatsurf.geometry.polygon import rectangle
return rectangle(2*self.get_black(lab),self.get_white(lab))
def polygon_labels(self):
r"""
The set of labels used for the polygons.
"""
return ZZ
def opposite_edge(self, p, e):
r"""
Return the pair ``(pp,ee)`` to which the edge ``(p,e)`` is glued to.
"""
if p==0:
if e==0:
return (0,2)
if e==1:
return (1,3)
if e==2:
return (0,0)
if e==3:
return (1,1)
if p==1:
if e==0:
return (-1,2)
if e==1:
return (0,3)
if e==2:
return (2,0)
if e==3:
return (0,1)
if p==-1:
if e==0:
return (2,2)
if e==1:
return (-1,3)
if e==2:
return (1,0)
if e==3:
return (-1,1)
if p==2:
if e==0:
return (1,2)
if e==1:
return (-2,3)
if e==2:
return (-1,0)
if e==3:
return (-2,1)
if p>2:
if e%2:
return -p,(e+2)%4
else:
return 1-p,(e+2)%4
else:
if e%2:
return -p,(e+2)%4
else:
return 1-p,(e+2)%4
def is_finite(self):
return False
def polyhedron_to_cone_surface(polyhedron, use_AA=False, scaling_factor=ZZ(1)):
r"""Construct the Euclidean Cone Surface associated to the surface of a polyhedron and a map
from the cone surface to the polyhedron.
INPUT:
- ``polyhedron`` -- A 3-dimensional polyhedron, which should be define over something that coerces into AA
- ``use_AA`` -- If True, the surface returned will be defined over AA. If false, the algorithm will find the smallest NumberField and write the field there.
- ``scaling_factor`` -- The surface returned will have a metric scaled by multiplication by this factor (compared with the original polyhendron). This can be used to produce a surface defined over a smaller NumberField.
OUTPUT:
A pair consisting of a ConeSurface and a ConeSurfaceToPolyhedronMap.
EXAMPLES::
sage: from flatsurf.geometry.polyhedra import *
sage: vertices=[]
sage: for i in range(3):
....: temp=vector([1 if k==i else 0 for k in range(3)])
....: for j in range(-1,3,2):
....: vertices.append(j*temp)
sage: octahedron=Polyhedron(vertices=vertices)
sage: surface,surface_to_octahedron = \
....: polyhedron_to_cone_surface(octahedron,scaling_factor=AA(1/sqrt(2)))
sage: TestSuite(surface).run()
sage: TestSuite(surface_to_octahedron).run(skip="_test_pickling")
sage: surface.num_polygons()
8
sage: surface.base_ring()
Number Field in a with defining polynomial y^2 - 3 with a = 1.732050807568878?
sage: sqrt3=surface.base_ring().gen()
sage: tangent_bundle=surface.tangent_bundle()
sage: v=tangent_bundle(0,(0,0),(sqrt3,2))
sage: traj=v.straight_line_trajectory()
sage: traj.flow(10)
sage: traj.is_saddle_connection()
True
sage: traj.combinatorial_length()
8
sage: path3d = surface_to_octahedron(traj)
sage: len(path3d)
9
sage: # We will show that the length of the path is sqrt(42):
sage: total_length = 0
sage: for i in range(8):
....: start = path3d[i]
....: end = path3d[i+1]
....: total_length += (vector(end)-vector(start)).norm()
sage: ZZ(total_length**2)
42
"""
assert polyhedron.dim() == 3
c = polyhedron.center()
vertices = polyhedron.vertices()
vertex_order = {}
for i, v in enumerate(vertices):
vertex_order[v] = i
faces = polyhedron.faces(2)
face_order = {}
face_edges = []
face_vertices = []
face_map_data = []
for i, f in enumerate(faces):
face_order[f] = i
edges = f.as_polyhedron().faces(1)
face_edges_temp = set()
for edge in edges:
edge_temp = set()
for vertex in edge.vertices():
v = vertex.vector()
v.set_immutable()
edge_temp.add(v)
face_edges_temp.add(frozenset(edge_temp))
last_edge = next(iter(face_edges_temp))
v = next(iter(last_edge))
face_vertices_temp = [v]
for j in range(len(face_edges_temp) - 1):
for edge in face_edges_temp:
if v in edge and edge != last_edge:
# bingo
last_edge = edge
for vv in edge:
if vv != v:
v = vv
face_vertices_temp.append(vv)
break
break
v0 = face_vertices_temp[0]
v1 = face_vertices_temp[1]
v2 = face_vertices_temp[2]
n = (v1 - v0).cross_product(v2 - v0)
if (v0 - c).dot_product(n) < 0:
n = -n
face_vertices_temp.reverse()
v0 = face_vertices_temp[0]
v1 = face_vertices_temp[1]
v2 = face_vertices_temp[2]
face_vertices.append(face_vertices_temp)
n = n / AA(n.norm())
w = v1 - v0
w = w / AA(w.norm())
m = 1 / scaling_factor * matrix(
AA, [w, n.cross_product(w), n]).transpose()
mi = ~m
mis = mi.submatrix(0, 0, 2, 3)
face_map_data.append((
v0, # translation to bring origin in plane to v0
m.submatrix(0, 0, 3, 2),
-mis * v0,
mis))
it = iter(face_vertices_temp)
v_last = next(it)
face_edge_dict = {}
j = 0
for v in it:
edge = frozenset([v_last, v])
face_edge_dict[edge] = j
j += 1
v_last = v
v = next(iter(face_vertices_temp))
edge = frozenset([v_last, v])
face_edge_dict[edge] = j
face_edges.append(face_edge_dict)
gluings = {}
for p1, face_edge_dict1 in enumerate(face_edges):
for edge, e1 in face_edge_dict1.items():
found = False
for p2, face_edge_dict2 in enumerate(face_edges):
if p1 != p2 and edge in face_edge_dict2:
e2 = face_edge_dict2[edge]
gluings[(p1, e1)] = (p2, e2)
found = True
break
if not found:
print(p1)
print(e1)
print(edge)
raise RuntimeError("Failed to find glued edge")
polygon_vertices_AA = []
for p, vs in enumerate(face_vertices):
trans = face_map_data[p][2]
m = face_map_data[p][3]
polygon_vertices_AA.append([trans + m * v for v in vs])
if use_AA == True:
Polys = ConvexPolygons(AA)
polygons = []
for vs in polygon_vertices_AA:
polygons.append(Polys(vertices=vs))
S = ConeSurface(
surface_list_from_polygons_and_gluings(polygons, gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
else:
elts = []
for vs in polygon_vertices_AA:
for v in vs:
elts.append(v[0])
elts.append(v[1])
# Find the best number field:
field, elts2, hom = number_field_elements_from_algebraics(elts,
minimal=True)
if field == QQ:
# Defined over the rationals!
polygon_vertices_field2 = []
j = 0
for vs in polygon_vertices_AA:
vs2 = []
for v in vs:
vs2.append(vector(field, [elts2[j], elts2[j + 1]]))
j = j + 2
polygon_vertices_field2.append(vs2)
Polys = ConvexPolygons(field)
polygons = []
for vs in polygon_vertices_field2:
polygons.append(Polys(vertices=vs))
S = ConeSurface(
surface_list_from_polygons_and_gluings(polygons, gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
else:
# Unfortunately field doesn't come with an real embedding (which is given by hom!)
# So, we make a copy of the field, and add the embedding.
field2 = NumberField(field.polynomial(),
name="a",
embedding=hom(field.gen()))
# The following converts from field to field2:
hom2 = field.hom(im_gens=[field2.gen()])
polygon_vertices_field2 = []
j = 0
for vs in polygon_vertices_AA:
vs2 = []
for v in vs:
vs2.append(
vector(field2, [hom2(elts2[j]),
hom2(elts2[j + 1])]))
j = j + 2
polygon_vertices_field2.append(vs2)
Polys = ConvexPolygons(field2)
polygons = []
for vs in polygon_vertices_field2:
polygons.append(Polys(vertices=vs))
S = ConeSurface(
surface_list_from_polygons_and_gluings(polygons, gluings))
return S, \
ConeSurfaceToPolyhedronMap(S,polyhedron,face_map_data)
