def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
"""
self._matrix = coxeter_matrix
self._index_set = index_set
n = ZZ(coxeter_matrix.nrows())
MS = MatrixSpace(base_ring, n, sparse=True)
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
if base_ring is UniversalCyclotomicField():
val = lambda x: base_ring.gen(2*x) + ~base_ring.gen(2*x) if x != -1 else base_ring(2)
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
val = lambda x: base_ring(2*cos(pi / x)) if x != -1 else base_ring(2)
gens = [MS.one() + MS({(i, j): val(coxeter_matrix[i, j])
for j in range(n)})
for i in range(n)]
FinitelyGeneratedMatrixGroup_generic.__init__(self, n, base_ring,
gens,
category=CoxeterGroups())
def __init__(self, n):
r"""
Hecke triangle group (2, n, infinity).
Namely the von Dyck group corresponding to the triangle group
with angles (pi/2, pi/n, 0).
INPUT:
- ``n`` - ``infinity`` or an integer greater or equal to ``3``.
OUTPUT:
The Hecke triangle group for the given parameter ``n``.
EXAMPLES::
sage: G = HeckeTriangleGroup(12)
sage: G
Hecke triangle group for n = 12
sage: G.category()
Category of groups
"""
self._n = n
self._T = matrix(AA, [[1,self.lam()],[0,1]])
self._S = matrix(AA, [[0,-1],[1,0]])
FinitelyGeneratedMatrixGroup_generic.__init__(self, ZZ(2), AA, [self._S, self._T])
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
"""
self._matrix = coxeter_matrix
self._index_set = index_set
n = ZZ(coxeter_matrix.nrows())
MS = MatrixSpace(base_ring, n, sparse=True)
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
if base_ring is UniversalCyclotomicField():
val = lambda x: base_ring.gen(2*x) + ~base_ring.gen(2*x) if x != -1 else base_ring(2)
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
val = lambda x: base_ring(2*cos(pi / x)) if x != -1 else base_ring(2)
gens = [MS.one() + MS({(i, j): val(coxeter_matrix[i, j])
for j in range(n)})
for i in range(n)]
FinitelyGeneratedMatrixGroup_generic.__init__(self, n, base_ring,
gens,
category=CoxeterGroups())
def __init__(self, n):
r"""
Hecke triangle group (2, n, infinity).
Namely the von Dyck group corresponding to the triangle group
with angles (pi/2, pi/n, 0).
INPUT:
- ``n`` - ``infinity`` or an integer greater or equal to ``3``.
OUTPUT:
The Hecke triangle group for the given parameter ``n``.
EXAMPLES::
sage: from sage.modular.modform_hecketriangle.hecke_triangle_groups import HeckeTriangleGroup
sage: G = HeckeTriangleGroup(12)
sage: G
Hecke triangle group for n = 12
sage: G.category()
Category of groups
"""
self._n = n
self.element_repr_method("default")
if n in [3, infinity]:
self._base_ring = ZZ
self._lam = ZZ(1) if n == 3 else ZZ(2)
else:
lam_symbolic = 2 * cos(pi / n)
K = NumberField(self.lam_minpoly(),
'lam',
embedding=coerce_AA(lam_symbolic))
#self._base_ring = K.order(K.gens())
self._base_ring = K.maximal_order()
self._lam = self._base_ring.gen(1)
T = matrix(self._base_ring, [[1, self._lam], [0, 1]])
S = matrix(self._base_ring, [[0, -1], [1, 0]])
FinitelyGeneratedMatrixGroup_generic.__init__(self, ZZ(2),
self._base_ring, [S, T])
def __init__(self, n):
r"""
Hecke triangle group (2, n, infinity).
Namely the von Dyck group corresponding to the triangle group
with angles (pi/2, pi/n, 0).
INPUT:
- ``n`` - ``infinity`` or an integer greater or equal to ``3``.
OUTPUT:
The Hecke triangle group for the given parameter ``n``.
EXAMPLES::
sage: from sage.modular.modform_hecketriangle.hecke_triangle_groups import HeckeTriangleGroup
sage: G = HeckeTriangleGroup(12)
sage: G
Hecke triangle group for n = 12
sage: G.category()
Category of groups
"""
self._n = n
self.element_repr_method("default")
if n in [3, infinity]:
self._base_ring = ZZ
self._lam = ZZ(1) if n==3 else ZZ(2)
else:
lam_symbolic = 2*cos(pi/n)
K = NumberField(self.lam_minpoly(), 'lam', embedding = coerce_AA(lam_symbolic))
#self._base_ring = K.order(K.gens())
self._base_ring = K.maximal_order()
self._lam = self._base_ring.gen(1)
T = matrix(self._base_ring, [[1,self._lam],[0,1]])
S = matrix(self._base_ring, [[0,-1],[1,0]])
FinitelyGeneratedMatrixGroup_generic.__init__(self, ZZ(2), self._base_ring, [S, T])
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
We check that :trac:`16630` is fixed::
sage: CoxeterGroup(['D',4], base_ring=QQ).category()
Category of finite coxeter groups
sage: CoxeterGroup(['H',4], base_ring=QQbar).category()
Category of finite coxeter groups
sage: F = CoxeterGroups().Finite()
sage: all(CoxeterGroup([letter,i]) in F
....: for i in range(2,5) for letter in ['A','B','D'])
True
sage: all(CoxeterGroup(['E',i]) in F for i in range(6,9))
True
sage: CoxeterGroup(['F',4]).category()
Category of finite coxeter groups
sage: CoxeterGroup(['G',2]).category()
Category of finite coxeter groups
sage: all(CoxeterGroup(['H',i]) in F for i in range(3,5))
True
sage: all(CoxeterGroup(['I',i]) in F for i in range(2,5))
True
"""
self._matrix = coxeter_matrix
n = coxeter_matrix.rank()
# Compute the matrix with entries `2 \cos( \pi / m_{ij} )`.
MS = MatrixSpace(base_ring, n, sparse=True)
MC = MS._get_matrix_class()
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
if base_ring is UniversalCyclotomicField():
val = lambda x: base_ring.gen(2*x) + ~base_ring.gen(2*x) if x != -1 else base_ring(2)
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
val = lambda x: base_ring(2*cos(pi / x)) if x != -1 else base_ring(2)
gens = [MS.one() + MC(MS, entries={(i, j): val(coxeter_matrix[index_set[i], index_set[j]])
for j in range(n)},
coerce=True, copy=True)
for i in range(n)]
category = CoxeterGroups()
# Now we shall see if the group is finite, and, if so, refine
# the category to ``category.Finite()``. Otherwise the group is
# infinite and we refine the category to ``category.Infinite()``.
if self._matrix.is_finite():
category = category.Finite()
else:
category = category.Infinite()
FinitelyGeneratedMatrixGroup_generic.__init__(self, ZZ(n), base_ring,
gens, category=category)
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
We check that :trac:`16630` is fixed::
sage: CoxeterGroup(['D',4], base_ring=QQ).category()
Category of finite coxeter groups
sage: CoxeterGroup(['H',4], base_ring=QQbar).category()
Category of finite coxeter groups
sage: F = CoxeterGroups().Finite()
sage: all(CoxeterGroup([letter,i]) in F
....: for i in range(2,5) for letter in ['A','B','D'])
True
sage: all(CoxeterGroup(['E',i]) in F for i in range(6,9))
True
sage: CoxeterGroup(['F',4]).category()
Category of finite coxeter groups
sage: CoxeterGroup(['G',2]).category()
Category of finite coxeter groups
sage: all(CoxeterGroup(['H',i]) in F for i in range(3,5))
True
sage: all(CoxeterGroup(['I',i]) in F for i in range(2,5))
True
"""
self._matrix = coxeter_matrix
n = coxeter_matrix.rank()
# Compute the matrix with entries `2 \cos( \pi / m_{ij} )`.
MS = MatrixSpace(base_ring, n, sparse=True)
MC = MS._get_matrix_class()
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
E = UniversalCyclotomicField().gen
if base_ring is UniversalCyclotomicField():
def val(x):
if x == -1:
return 2
else:
return E(2 * x) + ~E(2 * x)
elif is_QuadraticField(base_ring):
def val(x):
if x == -1:
return 2
else:
return base_ring(
(E(2 * x) + ~E(2 * x)).to_cyclotomic_field())
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
def val(x):
if x == -1:
return 2
else:
return base_ring(2 * cos(pi / x))
gens = [
MS.one() +
MC(MS,
entries={(i, j): val(coxeter_matrix[index_set[i], index_set[j]])
for j in range(n)},
coerce=True,
copy=True) for i in range(n)
]
# Make the generators dense matrices for consistency and speed
gens = [g.dense_matrix() for g in gens]
category = CoxeterGroups()
# Now we shall see if the group is finite, and, if so, refine
# the category to ``category.Finite()``. Otherwise the group is
# infinite and we refine the category to ``category.Infinite()``.
if self._matrix.is_finite():
category = category.Finite()
else:
category = category.Infinite()
self._index_set_inverse = {
i: ii
for ii, i in enumerate(self._matrix.index_set())
}
FinitelyGeneratedMatrixGroup_generic.__init__(self,
ZZ(n),
base_ring,
gens,
category=category)
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
We check that :trac:`16630` is fixed::
sage: CoxeterGroup(['D',4], base_ring=QQ).category()
Category of finite coxeter groups
sage: CoxeterGroup(['H',4], base_ring=QQbar).category()
Category of finite coxeter groups
sage: F = CoxeterGroups().Finite()
sage: all(CoxeterGroup([letter,i]) in F
....: for i in range(2,5) for letter in ['A','B','D'])
True
sage: all(CoxeterGroup(['E',i]) in F for i in range(6,9))
True
sage: CoxeterGroup(['F',4]).category()
Category of finite coxeter groups
sage: CoxeterGroup(['G',2]).category()
Category of finite coxeter groups
sage: all(CoxeterGroup(['H',i]) in F for i in range(3,5))
True
sage: all(CoxeterGroup(['I',i]) in F for i in range(2,5))
True
"""
self._matrix = coxeter_matrix
self._index_set = index_set
n = ZZ(coxeter_matrix.nrows())
# Compute the matrix with entries `2 \cos( \pi / m_{ij} )`.
MS = MatrixSpace(base_ring, n, sparse=True)
MC = MS._get_matrix_class()
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
if base_ring is UniversalCyclotomicField():
val = lambda x: base_ring.gen(2 * x) + ~base_ring.gen(2 * x) if x != -1 else base_ring(2)
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
val = lambda x: base_ring(2 * cos(pi / x)) if x != -1 else base_ring(2)
gens = [
MS.one() + MC(MS, entries={(i, j): val(coxeter_matrix[i, j]) for j in range(n)}, coerce=True, copy=True)
for i in range(n)
]
# Compute the matrix with entries `- \cos( \pi / m_{ij} )`.
# This describes the bilinear form corresponding to this
# Coxeter system, and might lead us out of our base ring.
base_field = base_ring.fraction_field()
MS2 = MatrixSpace(base_field, n, sparse=True)
MC2 = MS2._get_matrix_class()
self._bilinear = MC2(
MS2,
entries={
(i, j): val(coxeter_matrix[i, j]) / base_field(-2)
for i in range(n)
for j in range(n)
if coxeter_matrix[i, j] != 2
},
coerce=True,
copy=True,
)
self._bilinear.set_immutable()
category = CoxeterGroups()
# Now we shall see if the group is finite, and, if so, refine
# the category to ``category.Finite()``. Otherwise the group is
# infinite and we refine the category to ``category.Infinite()``.
is_finite = self._finite_recognition()
if is_finite:
category = category.Finite()
else:
category = category.Infinite()
FinitelyGeneratedMatrixGroup_generic.__init__(self, n, base_ring, gens, category=category)
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
We check that :trac:`16630` is fixed::
sage: CoxeterGroup(['D',4], base_ring=QQ).category()
Category of finite irreducible coxeter groups
sage: CoxeterGroup(['H',4], base_ring=QQbar).category()
Category of finite irreducible coxeter groups
sage: F = CoxeterGroups().Finite()
sage: all(CoxeterGroup([letter,i]) in F
....: for i in range(2,5) for letter in ['A','B','D'])
True
sage: all(CoxeterGroup(['E',i]) in F for i in range(6,9))
True
sage: CoxeterGroup(['F',4]).category()
Category of finite irreducible coxeter groups
sage: CoxeterGroup(['G',2]).category()
Category of finite irreducible coxeter groups
sage: all(CoxeterGroup(['H',i]) in F for i in range(3,5))
True
sage: all(CoxeterGroup(['I',i]) in F for i in range(2,5))
True
"""
self._matrix = coxeter_matrix
n = coxeter_matrix.rank()
# Compute the matrix with entries `2 \cos( \pi / m_{ij} )`.
MS = MatrixSpace(base_ring, n, sparse=True)
one = MS.one()
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
E = UniversalCyclotomicField().gen
if base_ring is UniversalCyclotomicField():
def val(x):
if x == -1:
return 2
else:
return E(2 * x) + ~E(2 * x)
elif is_QuadraticField(base_ring):
def val(x):
if x == -1:
return 2
else:
return base_ring((E(2 * x) + ~E(2 * x)).to_cyclotomic_field())
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
def val(x):
if x == -1:
return 2
else:
return base_ring(2 * cos(pi / x))
gens = [one + MS([SparseEntry(i, j, val(coxeter_matrix[index_set[i], index_set[j]]))
for j in range(n)])
for i in range(n)]
# Make the generators dense matrices for consistency and speed
gens = [g.dense_matrix() for g in gens]
category = CoxeterGroups()
# Now we shall see if the group is finite, and, if so, refine
# the category to ``category.Finite()``. Otherwise the group is
# infinite and we refine the category to ``category.Infinite()``.
if self._matrix.is_finite():
category = category.Finite()
else:
category = category.Infinite()
if all(self._matrix._matrix[i, j] == 2
for i in range(n) for j in range(i)):
category = category.Commutative()
if self._matrix.is_irreducible():
category = category.Irreducible()
self._index_set_inverse = {i: ii
for ii, i in enumerate(self._matrix.index_set())}
FinitelyGeneratedMatrixGroup_generic.__init__(self, ZZ(n), base_ring,
gens, category=category)
def __init__(self, coxeter_matrix, base_ring, index_set):
"""
Initialize ``self``.
EXAMPLES::
sage: W = CoxeterGroup([[1,3,2],[3,1,3],[2,3,1]])
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,4],[2,4,1]], base_ring=QQbar)
sage: TestSuite(W).run() # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,6],[2,6,1]])
sage: TestSuite(W).run(max_runs=30) # long time
sage: W = CoxeterGroup([[1,3,2],[3,1,-1],[2,-1,1]])
sage: TestSuite(W).run(max_runs=30) # long time
We check that :trac:`16630` is fixed::
sage: CoxeterGroup(['D',4], base_ring=QQ).category()
Category of finite coxeter groups
sage: CoxeterGroup(['H',4], base_ring=QQbar).category()
Category of finite coxeter groups
sage: F = CoxeterGroups().Finite()
sage: all(CoxeterGroup([letter,i]) in F
....: for i in range(2,5) for letter in ['A','B','D'])
True
sage: all(CoxeterGroup(['E',i]) in F for i in range(6,9))
True
sage: CoxeterGroup(['F',4]).category()
Category of finite coxeter groups
sage: CoxeterGroup(['G',2]).category()
Category of finite coxeter groups
sage: all(CoxeterGroup(['H',i]) in F for i in range(3,5))
True
sage: all(CoxeterGroup(['I',i]) in F for i in range(2,5))
True
"""
self._matrix = coxeter_matrix
self._index_set = index_set
n = ZZ(coxeter_matrix.nrows())
# Compute the matrix with entries `2 \cos( \pi / m_{ij} )`.
MS = MatrixSpace(base_ring, n, sparse=True)
MC = MS._get_matrix_class()
# FIXME: Hack because there is no ZZ \cup \{ \infty \}: -1 represents \infty
if base_ring is UniversalCyclotomicField():
val = lambda x: base_ring.gen(2 * x) + ~base_ring.gen(
2 * x) if x != -1 else base_ring(2)
else:
from sage.functions.trig import cos
from sage.symbolic.constants import pi
val = lambda x: base_ring(2 * cos(pi / x)
) if x != -1 else base_ring(2)
gens = [
MS.one() + MC(MS,
entries={(i, j): val(coxeter_matrix[i, j])
for j in range(n)},
coerce=True,
copy=True) for i in range(n)
]
# Compute the matrix with entries `- \cos( \pi / m_{ij} )`.
# This describes the bilinear form corresponding to this
# Coxeter system, and might lead us out of our base ring.
base_field = base_ring.fraction_field()
MS2 = MatrixSpace(base_field, n, sparse=True)
MC2 = MS2._get_matrix_class()
self._bilinear = MC2(MS2,
entries={
(i, j):
val(coxeter_matrix[i, j]) / base_field(-2)
for i in range(n) for j in range(n)
if coxeter_matrix[i, j] != 2
},
coerce=True,
copy=True)
self._bilinear.set_immutable()
category = CoxeterGroups()
# Now we shall see if the group is finite, and, if so, refine
# the category to ``category.Finite()``. Otherwise the group is
# infinite and we refine the category to ``category.Infinite()``.
is_finite = self._finite_recognition()
if is_finite:
category = category.Finite()
else:
category = category.Infinite()
FinitelyGeneratedMatrixGroup_generic.__init__(self,
n,
base_ring,
gens,
category=category)
