def add_row(A, b, pivots, include_zero_rows):
"""
The add row procedure.
INPUT:
A -- a matrix in Hermite normal form with n column
b -- an n x 1 row matrix
pivots -- sorted list of integers; the pivot positions of A.
OUTPUT:
H -- the Hermite normal form of A.stack(b).
new_pivots -- the pivot columns of H.
EXAMPLES:
sage: import sage.matrix.matrix_integer_dense_hnf as hnf
sage: A = matrix(ZZ, 2, 3, [-21, -7, 5, 1,20,-7])
sage: b = matrix(ZZ, 1,3, [-1,1,-1])
sage: hnf.add_row(A, b, A.pivots(), True)
(
[ 1 6 29]
[ 0 7 28]
[ 0 0 46], [0, 1, 2]
)
sage: A.stack(b).echelon_form()
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
"""
t = verbose('add hnf row')
v = b.row(0)
H, pivs = A._add_row_and_maintain_echelon_form(b.row(0), pivots)
if include_zero_rows and H.nrows() != A.nrows()+1:
H = H.matrix_from_rows(range(A.nrows()+1))
verbose('finished add hnf row', t)
return H, pivs
def hecke_bound(self):
r"""
Return an integer B such that the Hecke operators `T_n`, for `n\leq B`,
generate the full Hecke algebra as a module over the base ring. Note
that we include the `n` with `n` not coprime to the level.
At present this returns an unproven guess for non-cuspidal spaces which
appears to be valid for `M_k(\Gamma_0(N))`, where k and N are the
weight and level of self. (It is clearly valid for *cuspidal* spaces
of any fixed character, as a consequence of the Sturm bound theorem.)
It returns a hopelessly wrong answer for spaces of full level
`\Gamma_1`.
TODO: Get rid of this dreadful bit of code.
EXAMPLE::
sage: ModularSymbols(17, 4).hecke_bound()
15
sage: ModularSymbols(Gamma1(17), 4).hecke_bound() # wrong!
15
"""
try:
if self.is_cuspidal():
return Gamma0(self.level()).sturm_bound(self.weight())
except AttributeError:
pass
misc.verbose("WARNING: ambient.py -- hecke_bound; returning unproven guess.")
return Gamma0(self.level()).sturm_bound(self.weight()) + 2*Gamma0(self.level()).dimension_eis(self.weight()) + 5
def extract_ones_data(H, pivots):
"""
Compute ones data and corresponding submatrices of H. This is
used to optimized the add_row function.
INPUT:
- H -- a matrix in HNF
- pivots -- list of all pivot column positions of H
OUTPUT:
C, D, E, onecol, onerow, non_onecol, non_onerow
where onecol, onerow, non_onecol, non_onerow are as for
the ones function, and C, D, E are matrices:
- C -- submatrix of all non-onecol columns and onecol rows
- D -- all non-onecol columns and other rows
- E -- inverse of D
If D isn't invertible or there are 0 or more than 2 non onecols,
then C, D, and E are set to None.
EXAMPLES::
sage: H = matrix(ZZ, 3, 4, [1, 0, 0, 7, 0, 1, 5, 2, 0, 0, 6, 6])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.extract_ones_data(H, [0,1,2])
(
[0]
[5], [6], [1/6], [0, 1], [0, 1], [2], [2]
)
Here we get None's since the (2,2) position submatrix is not invertible.
sage: H = matrix(ZZ, 3, 5, [1, 0, 0, 45, -36, 0, 1, 0, 131, -107, 0, 0, 0, 178, -145]); H
[ 1 0 0 45 -36]
[ 0 1 0 131 -107]
[ 0 0 0 178 -145]
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.extract_ones_data(H, [0,1,3])
(None, None, None, [0, 1], [0, 1], [2], [2])
"""
onecol, onerow, non_onecol, non_onerow = ones(H, pivots)
verbose('extract_ones -- got submatrix of size %s' % len(non_onecol))
if len(non_onecol) in [1, 2]:
# Extract submatrix of all non-onecol columns and onecol rows
C = H.matrix_from_rows_and_columns(onerow, non_onecol)
# Extract submatrix of all non-onecol columns and other rows
D = H.matrix_from_rows_and_columns(non_onerow, non_onecol).transpose()
tt = verbose("extract ones -- INVERT %s x %s" %
(len(non_onerow), len(non_onecol)),
level=1)
try:
E = D**(-1)
except ZeroDivisionError:
C = D = E = None
verbose("done inverting", tt, level=1)
return C, D, E, onecol, onerow, non_onecol, non_onerow
else:
return None, None, None, onecol, onerow, non_onecol, non_onerow
def _eval_line(self, line, reformat=True, allow_use_file=False,
wait_for_prompt=True, restart_if_needed=False):
"""
EXAMPLES::
sage: print octave._eval_line('2+2') #optional - octave
ans = 4
"""
if not wait_for_prompt:
return Expect._eval_line(self, line)
if line == '':
return ''
if self._expect is None:
self._start()
if allow_use_file and len(line)>3000:
return self._eval_line_using_file(line)
try:
E = self._expect
verbose("in = '%s'"%line,level=3)
E.sendline(line)
E.expect(self._prompt)
out = E.before
verbose("out = '%s'"%out,level=3)
except EOF:
if self._quit_string() in line:
return ''
except KeyboardInterrupt:
self._keyboard_interrupt()
if reformat:
if '>>> ' in out and 'syntax error' in out:
raise SyntaxError(out)
out = "\n".join(out.splitlines()[1:])
return out
def _next_var_name(self):
"""
Return the name of the next unused interface variable name.
EXAMPLES::
sage: g = Gp()
sage: g._next_var_name()
'sage[1]'
sage: g(2)^2
4
sage: g._next_var_name()
'sage[5]'
"""
self.__seq += 1
self.__seq %= 1000
#print 'wtf: %s' % self.__seq
if self.__seq >= self.__var_store_len:
if self.__var_store_len == 0:
self.eval('sage=vector(%s,k,0);'%self.__init_list_length)
self.__var_store_len = self.__init_list_length
else:
self.eval('sage=concat(sage, vector(%s,k,0));'%self.__var_store_len)
self.__var_store_len *= 2
verbose("doubling PARI/sage object vector: %s"%self.__var_store_len)
return 'sage[%s]'%self.__seq
def _step_upper_bound_internal(r, m, q, generating_function):
r"""
Common implementation for :func:`step_upper_bound` and :func:`step_upper_bound_specific`
"""
L = LieAlgebra(QQ, ['X_%d' % k for k in range(r)]).Lyndon()
dim_fm = L.graded_dimension(m)
t = var('t')
pt = symbolic_prod(
(1 / ((1 - t**k)**L.graded_dimension(k)) for k in range(1, m)),
(1 - dim_fm * (1 - t**q)) * t**m)
increment = series_precision()
i = 0
coeffsum = ZZ.zero()
while True:
# sum the coefficients of the series for t^i...t^(i+increment-1)
p_series = pt.series(t, i + increment)
for s in range(i, i + increment):
coeffsum += ZZ(p_series.coefficient(t, s))
if coeffsum > 0:
verbose("upper bound for abnormality: step %d" % s)
if generating_function:
return s, pt
return s
# exponential growth to avoid recomputing the series too much
i += increment
increment += increment
def cuspidal_submodule_q_expansion_basis(self, weight, prec=None):
r"""
Calculate a basis of `q`-expansions for the space of cusp forms of
weight ``weight`` for this group.
INPUT:
- ``weight`` (integer) -- the weight
- ``prec`` (integer or None) -- precision of `q`-expansions to return
ALGORITHM: Uses the method :meth:`cuspidal_ideal_generators` to
calculate generators of the ideal of cusp forms inside this ring. Then
multiply these up to weight ``weight`` using the generators of the
whole modular form space returned by :meth:`q_expansion_basis`.
EXAMPLES::
sage: R = ModularFormsRing(Gamma0(3))
sage: R.cuspidal_submodule_q_expansion_basis(20)
[q - 8532*q^6 - 88442*q^7 + O(q^8), q^2 + 207*q^6 + 24516*q^7 + O(q^8), q^3 + 456*q^6 + O(q^8), q^4 - 135*q^6 - 926*q^7 + O(q^8), q^5 + 18*q^6 + 135*q^7 + O(q^8)]
We compute a basis of a space of very large weight, quickly (using this
module) and slowly (using modular symbols), and verify that the answers
are the same. ::
sage: A = R.cuspidal_submodule_q_expansion_basis(80, prec=30) # long time (1s on sage.math, 2013)
sage: B = R.modular_forms_of_weight(80).cuspidal_submodule().q_expansion_basis(prec=30) # long time (19s on sage.math, 2013)
sage: A == B # long time
True
"""
d = self.modular_forms_of_weight(weight).cuspidal_submodule().dimension()
if d == 0: return []
minprec = self.modular_forms_of_weight(weight).sturm_bound()
if prec is None:
prec = working_prec = minprec
else:
working_prec = max(prec, minprec)
gen_weight = min(6, weight)
while 1:
verbose("Trying to generate the %s-dimensional cuspidal submodule at weight %s using generators of weight up to %s" % (d, weight, gen_weight))
G = self.cuspidal_ideal_generators(maxweight=gen_weight, prec=working_prec)
flist = []
for (j, f, F) in G:
for g in self.q_expansion_basis(weight - j, prec=working_prec):
flist.append(g*f)
A = self.base_ring() ** working_prec
W = A.span([A(f.padded_list(working_prec)) for f in flist])
if W.rank() == d and (self.base_ring().is_field() or W.index_in_saturation() == 1):
break
else:
gen_weight += 1
verbose("Need more generators: trying again with generators of weight up to %s" % gen_weight)
R = G[0][1].parent()
return [R(list(x), prec=prec) for x in W.gens()]
def _next_var_name(self):
"""
Return the name of the next unused interface variable name.
EXAMPLES::
sage: g = Gp()
sage: g._next_var_name()
'sage[1]'
sage: g(2)^2
4
sage: g._next_var_name()
'sage[5]'
"""
self.__seq += 1
if self.__seq >= self.__var_store_len:
if self.__var_store_len == 0:
self.eval('sage=vector(%s,k,0);' % self.__init_list_length)
self.__var_store_len = self.__init_list_length
else:
self.eval('sage=concat(sage, vector(%s,k,0));' %
self.__var_store_len)
self.__var_store_len *= 2
verbose("doubling PARI/sage object vector: %s" %
self.__var_store_len)
return 'sage[%s]' % self.__seq
def _eval_line(self, line, allow_use_file=True, wait_for_prompt=True, restart_if_needed=False):
"""
EXAMPLES::
sage: gp._eval_line('2+2')
'4'
TESTS:
We verify that :trac:`11617` is fixed::
sage: gp._eval_line('a='+str(list(range(2*10^5))))[:70]
'[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,'
"""
line = line.strip()
if len(line) == 0:
return ''
a = Expect._eval_line(self, line,
allow_use_file=allow_use_file,
wait_for_prompt=wait_for_prompt)
if a.find("the PARI stack overflows") != -1:
verbose("automatically doubling the PARI stack and re-executing current input line")
b = self.eval("allocatemem()")
if b.find("Warning: not enough memory") != -1:
raise RuntimeError(a)
return self._eval_line(line, allow_use_file=allow_use_file,
wait_for_prompt=wait_for_prompt)
else:
return a
def add_row(A, b, pivots, include_zero_rows):
"""
The add row procedure.
INPUT:
A -- a matrix in Hermite normal form with n column
b -- an n x 1 row matrix
pivots -- sorted list of integers; the pivot positions of A.
OUTPUT:
H -- the Hermite normal form of A.stack(b).
new_pivots -- the pivot columns of H.
EXAMPLES:
sage: import sage.matrix.matrix_integer_dense_hnf as hnf
sage: A = matrix(ZZ, 2, 3, [-21, -7, 5, 1,20,-7])
sage: b = matrix(ZZ, 1,3, [-1,1,-1])
sage: hnf.add_row(A, b, A.pivots(), True)
(
[ 1 6 29]
[ 0 7 28]
[ 0 0 46], [0, 1, 2]
)
sage: A.stack(b).echelon_form()
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
"""
t = verbose('add hnf row')
v = b.row(0)
H, pivs = A._add_row_and_maintain_echelon_form(b.row(0), pivots)
if include_zero_rows and H.nrows() != A.nrows() + 1:
H = H.matrix_from_rows(range(A.nrows() + 1))
verbose('finished add hnf row', t)
return H, pivs
def __call__(self, x):
r"""
Evaluate this character at an element of `\ZZ_p^\times`.
EXAMPLES::
sage: kappa = pAdicWeightSpace(23)(1 + 23^2 + O(23^20), 4, False)
sage: kappa(2)
16 + 7*23 + 7*23^2 + 16*23^3 + 23^4 + 20*23^5 + 15*23^7 + 11*23^8 + 12*23^9 + 8*23^10 + 22*23^11 + 16*23^12 + 13*23^13 + 4*23^14 + 19*23^15 + 6*23^16 + 7*23^17 + 11*23^19 + O(23^20)
sage: kappa(-1)
1 + O(23^20)
sage: kappa(23)
0
sage: kappa(2 + 2*23 + 11*23^2 + O(23^3))
16 + 7*23 + O(23^3)
"""
if not isinstance(x, pAdicGenericElement):
x = Qp(self._p)(x)
if x.valuation() != 0:
return 0
teich = x.parent().teichmuller(x)
xx = x / teich
if (xx - 1).valuation() <= 0:
raise ArithmeticError
verbose("Normalised element is %s" % xx)
e = xx.log() / self.parent()._param.log()
verbose("Exponent is %s" % e)
return teich**(self.t) * (self.w.log() * e).exp()
def hecke_bound(self):
r"""
Return an integer B such that the Hecke operators `T_n`, for `n\leq B`,
generate the full Hecke algebra as a module over the base ring. Note
that we include the `n` with `n` not coprime to the level.
At present this returns an unproven guess for non-cuspidal spaces which
appears to be valid for `M_k(\Gamma_0(N))`, where k and N are the
weight and level of self. (It is clearly valid for *cuspidal* spaces
of any fixed character, as a consequence of the Sturm bound theorem.)
It returns a hopelessly wrong answer for spaces of full level
`\Gamma_1`.
TODO: Get rid of this dreadful bit of code.
EXAMPLE::
sage: ModularSymbols(17, 4).hecke_bound()
15
sage: ModularSymbols(Gamma1(17), 4).hecke_bound() # wrong!
15
"""
try:
if self.is_cuspidal():
return Gamma0(self.level()).sturm_bound(self.weight())
except AttributeError:
pass
misc.verbose(
"WARNING: ambient.py -- hecke_bound; returning unproven guess.")
return Gamma0(self.level()).sturm_bound(self.weight()) + 2 * Gamma0(
self.level()).dimension_eis(self.weight()) + 5
def __call__(self, x):
r"""
Evaluate this character at an element of `\ZZ_p^\times`.
EXAMPLES::
sage: kappa = pAdicWeightSpace(23)(1 + 23^2 + O(23^20), 4, False)
sage: kappa(2)
16 + 7*23 + 7*23^2 + 16*23^3 + 23^4 + 20*23^5 + 15*23^7 + 11*23^8 + 12*23^9 + 8*23^10 + 22*23^11 + 16*23^12 + 13*23^13 + 4*23^14 + 19*23^15 + 6*23^16 + 7*23^17 + 11*23^19 + O(23^20)
sage: kappa(-1)
1 + O(23^20)
sage: kappa(23)
0
sage: kappa(2 + 2*23 + 11*23^2 + O(23^3))
16 + 7*23 + O(23^3)
"""
if not isinstance(x, pAdicGenericElement):
x = Qp(self._p)(x)
if x.valuation() != 0:
return 0
teich = x.parent().teichmuller(x, x.precision_absolute())
xx = x / teich
if (xx - 1).valuation() <= 0:
raise ArithmeticError
verbose("Normalised element is %s" % xx)
e = xx.log() / self.parent()._param.log()
verbose("Exponent is %s" % e)
return teich**(self.t) * (self.w.log() * e).exp()
def _eval_line(self, line, allow_use_file=True, wait_for_prompt=True, restart_if_needed=False):
"""
EXAMPLES::
sage: gp._eval_line('2+2')
'4'
TESTS:
We verify that trac 11617 is fixed::
sage: gp._eval_line('a='+str(range(2*10^5)))[:70]
'[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,'
"""
line = line.strip()
if len(line) == 0:
return ''
a = Expect._eval_line(self, line,
allow_use_file=allow_use_file,
wait_for_prompt=wait_for_prompt)
if a.find("the PARI stack overflows") != -1:
verbose("automatically doubling the PARI stack and re-executing current input line")
b = self.eval("allocatemem()")
if b.find("Warning: not enough memory") != -1:
raise RuntimeError(a)
return self._eval_line(line, allow_use_file=allow_use_file,
wait_for_prompt=wait_for_prompt)
else:
return a
def Tq_eigenvalue(self, q, p=None, M=None, check=True):
r"""
Eigenvalue of `T_q` modulo `p^M`
INPUT:
- ``q`` -- prime of the Hecke operator
- ``p`` -- prime we are working modulo (default: None)
- ``M`` -- degree of accuracy of approximation (default: None)
- ``check`` --
OUTPUT:
- Constant `c` such that `self|T_q - c * self` has valuation greater than
or equal to `M` (if it exists), otherwise raises ValueError
EXAMPLES::
sage: E = EllipticCurve('11a')
sage: from sage.modular.pollack_stevens.space import ps_modsym_from_elliptic_curve
sage: phi = ps_modsym_from_elliptic_curve(E)
sage: phi.values()
[-1/5, 3/2, -1/2]
sage: phi_ord = phi.p_stabilize(p = 3, ap = E.ap(3), M = 10, ordinary = True)
sage: phi_ord.Tq_eigenvalue(2,3,10) + 2
O(3^10)
sage: phi_ord.Tq_eigenvalue(3,3,10)
2 + 3^2 + 2*3^3 + 2*3^4 + 2*3^6 + 3^8 + 2*3^9 + O(3^10)
sage: phi_ord.Tq_eigenvalue(3,3,100)
Traceback (most recent call last):
...
ValueError: not a scalar multiple
"""
qhecke = self.hecke(q)
gens = self.parent().source().gens()
if p is None:
p = self.parent().prime()
i = 0
g = gens[i]
verbose("Computing eigenvalue")
while self._map[g].is_zero(p, M):
if not qhecke._map[g].is_zero(p, M):
raise ValueError("not a scalar multiple")
i += 1
try:
g = gens[i]
except IndexError:
raise ValueError("self is zero")
aq = self._map[g].find_scalar(qhecke._map[g], p, M, check)
if check:
verbose("Checking that this is actually an eigensymbol")
if p is None or M is None:
for g in gens[1:]:
if qhecke._map[g] != aq * self._map[g]:
raise ValueError("not a scalar multiple")
elif (qhecke - aq * self).valuation(p) < M:
raise ValueError("not a scalar multiple")
return aq
def extract_ones_data(H, pivots):
"""
Compute ones data and corresponding submatrices of H. This is
used to optimized the add_row function.
INPUT:
- H -- a matrix in HNF
- pivots -- list of all pivot column positions of H
OUTPUT:
C, D, E, onecol, onerow, non_onecol, non_onerow
where onecol, onerow, non_onecol, non_onerow are as for
the ones function, and C, D, E are matrices:
- C -- submatrix of all non-onecol columns and onecol rows
- D -- all non-onecol columns and other rows
- E -- inverse of D
If D isn't invertible or there are 0 or more than 2 non onecols,
then C, D, and E are set to None.
EXAMPLES::
sage: H = matrix(ZZ, 3, 4, [1, 0, 0, 7, 0, 1, 5, 2, 0, 0, 6, 6])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.extract_ones_data(H, [0,1,2])
(
[0]
[5], [6], [1/6], [0, 1], [0, 1], [2], [2]
)
Here we get None's since the (2,2) position submatrix is not invertible.
sage: H = matrix(ZZ, 3, 5, [1, 0, 0, 45, -36, 0, 1, 0, 131, -107, 0, 0, 0, 178, -145]); H
[ 1 0 0 45 -36]
[ 0 1 0 131 -107]
[ 0 0 0 178 -145]
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.extract_ones_data(H, [0,1,3])
(None, None, None, [0, 1], [0, 1], [2], [2])
"""
onecol, onerow, non_onecol, non_onerow = ones(H, pivots)
verbose('extract_ones -- got submatrix of size %s'%len(non_onecol))
if len(non_onecol) in [1,2]:
# Extract submatrix of all non-onecol columns and onecol rows
C = H.matrix_from_rows_and_columns(onerow, non_onecol)
# Extract submatrix of all non-onecol columns and other rows
D = H.matrix_from_rows_and_columns(non_onerow, non_onecol).transpose()
tt = verbose("extract ones -- INVERT %s x %s"%(len(non_onerow), len(non_onecol)), level=1)
try:
E = D**(-1)
except ZeroDivisionError:
C = D = E = None
verbose("done inverting", tt, level=1)
return C, D, E, onecol, onerow, non_onecol, non_onerow
else:
return None, None, None, onecol, onerow, non_onecol, non_onerow
def __call__(self, z, prec=None):
r"""
Evaluate ``self`` at a point `z \in X_0(N)` where `z` is given by a
representative in the upper half plane.
All computations are done with ``prec``
bits of precision. If ``prec`` is not given, use the precision of `z`.
EXAMPLES::
sage: E = EllipticCurve('37a')
sage: phi = E.modular_parametrization()
sage: phi((sqrt(7)*I - 17)/74, 53)
(...e-16 - ...e-16*I : ...e-16 + ...e-16*I : 1.00000000000000)
Verify that the mapping is invariant under the action of `\Gamma_0(N)`
on the upper half plane::
sage: E = EllipticCurve('11a')
sage: phi = E.modular_parametrization()
sage: tau = CC((1+1j)/5)
sage: phi(tau)
(-3.92181329652811 - 12.2578555525366*I : 44.9649874434872 + 14.3257120944681*I : 1.00000000000000)
sage: phi(tau+1)
(-3.92181329652810 - 12.2578555525366*I : 44.9649874434872 + 14.3257120944681*I : 1.00000000000000)
sage: phi((6*tau+1) / (11*tau+2))
(-3.9218132965285... - 12.2578555525369*I : 44.964987443489... + 14.325712094467...*I : 1.00000000000000)
We can also apply the modular parametrization to a Heegner point on `X_0(N)`::
sage: H = heegner_points(389,-7,5); H
All Heegner points of conductor 5 on X_0(389) associated to QQ[sqrt(-7)]
sage: x = H[0]; x
Heegner point 5/778*sqrt(-7) - 147/778 of discriminant -7 and conductor 5 on X_0(389)
sage: E = EllipticCurve('389a'); phi = E.modular_parametrization()
sage: phi(x)
Heegner point of discriminant -7 and conductor 5 on elliptic curve of conductor 389
sage: phi(x).quadratic_form()
389*x^2 + 147*x*y + 14*y^2
ALGORITHM:
Integrate the modular form attached to this elliptic curve from
`z` to `\infty` to get a point on the lattice representation of
`E`, then use the Weierstrass `\wp` function to map it to the
curve itself.
"""
if isinstance(z, heegner.HeegnerPointOnX0N):
return z.map_to_curve(self.curve())
# Map to the CC of CC/PeriodLattice.
tm = verbose(
"Evaluating modular parameterization to precision %s bits" % prec)
w = self.map_to_complex_numbers(z, prec=prec)
# Map to E via Weierstrass P
z = self._E.elliptic_exponential(w)
verbose("Finished evaluating modular parameterization", tm)
return z
def modS_relations(syms):
"""
Compute quotient of Manin symbols by the S relations.
Here S is the 2x2 matrix [0, -1; 1, 0].
INPUT:
- ``syms`` - manin_symbols.ManinSymbols
OUTPUT:
- ``rels`` - set of pairs of pairs (j, s), where if
mod[i] = (j,s), then x_i = s\*x_j (mod S relations)
EXAMPLES::
sage: from sage.modular.modsym.manin_symbols import ManinSymbolList_gamma0
sage: from sage.modular.modsym.relation_matrix import modS_relations
::
sage: syms = ManinSymbolList_gamma0(2, 4); syms
Manin Symbol List of weight 4 for Gamma0(2)
sage: modS_relations(syms)
set([((3, -1), (4, 1)), ((5, -1), (5, 1)), ((1, 1), (6, 1)), ((0, 1), (7, 1)), ((3, 1), (4, -1)), ((2, 1), (8, 1))])
::
sage: syms = ManinSymbolList_gamma0(7, 2); syms
Manin Symbol List of weight 2 for Gamma0(7)
sage: modS_relations(syms)
set([((3, 1), (4, 1)), ((2, 1), (7, 1)), ((5, 1), (6, 1)), ((0, 1), (1, 1))])
Next we do an example with Gamma1::
sage: from sage.modular.modsym.manin_symbols import ManinSymbolList_gamma1
sage: syms = ManinSymbolList_gamma1(3,2); syms
Manin Symbol List of weight 2 for Gamma1(3)
sage: modS_relations(syms)
set([((3, 1), (6, 1)), ((0, 1), (5, 1)), ((0, 1), (2, 1)), ((3, 1), (4, 1)), ((6, 1), (7, 1)), ((1, 1), (2, 1)), ((1, 1), (5, 1)), ((4, 1), (7, 1))])
"""
if not isinstance(syms, manin_symbols.ManinSymbolList):
raise TypeError, "syms must be a ManinSymbolList"
tm = misc.verbose()
# We will fill in this set with the relations x_i + s*x_j = 0,
# where the notation is as in _sparse_2term_quotient.
rels = set()
for i in xrange(len(syms)):
j, s = syms.apply_S(i)
assert j != -1
if i < j:
rels.add(((i, 1), (j, s)))
else:
rels.add(((j, s), (i, 1)))
misc.verbose("finished creating S relations", tm)
return rels
def _find_alpha(self, p, k, M=None, ap=None, new_base_ring=None, ordinary=True, check=True, find_extraprec=True):
"""
Finds `alpha`, a `U_p` eigenvalue, which is found as a root of
the polynomial `x^2 - ap * x + p^(k+1)`.
INPUT:
- ``p`` -- prime
- ``k`` -- Pollack-Stevens weight
- ``M`` -- precision (default = None) of `Q_p`
- ``ap`` -- Hecke eigenvalue at p (default = None)
- ``new_base_ring`` -- field of definition of `alpha` (default = None)
- ``ordinary`` -- True if the prime is ordinary (default = True)
- ``check`` -- check to see if the prime is ordinary (default = True)
- ``find_extraprec`` -- setting this to True finds extra precision (default = True)
OUTPUT:
- ``alpha`` -- `U_p` eigenvalue
- ``new_base_ring`` -- field of definition of `alpha` with precision at least `newM`
- ``newM`` -- new precision
- ``eisenloss`` -- loss of precision
- ``q`` -- a prime not equal to p which was used to find extra precision
- ``aq`` -- the Hecke eigenvalue `aq` corresponding to `q`
EXAMPLES::
sage: from sage.modular.pollack_stevens.space import ps_modsym_from_elliptic_curve
sage: E = EllipticCurve('11a')
sage: p = 5
sage: M = 10
sage: k = 0
sage: phi = ps_modsym_from_elliptic_curve(E)
sage: phi._find_alpha(p,k,M)
(1 + 4*5 + 3*5^2 + 2*5^3 + 4*5^4 + 4*5^5 + 4*5^6 + 3*5^7 + 2*5^8 + 3*5^9 + 3*5^10 + 3*5^12 + O(5^13), 5-adic Field with capped relative precision 13, 12, 1, None, None)
"""
if ap is None:
ap = self.Tq_eigenvalue(p, check=check)
if check and ap.valuation(p) > 0:
raise ValueError("p is not ordinary")
poly = PolynomialRing(ap.parent(), 'x')([p**(k+1), -ap, 1])
if new_base_ring is None:
# These should actually be completions of disc.parent()
if p == 2:
# is this the right precision adjustment for p=2?
new_base_ring = Qp(2, M+1)
else:
new_base_ring = Qp(p, M)
set_padicbase = True
else:
set_padicbase = False
try:
verbose("finding alpha: rooting %s in %s"%(poly, new_base_ring))
(v0,e0),(v1,e1) = poly.roots(new_base_ring)
except TypeError, ValueError:
raise ValueError("new base ring must contain a root of x^2 - ap * x + p^(k+1)")
def __call__(self, z, prec=None):
r"""
Evaluate ``self`` at a point `z \in X_0(N)` where `z` is given by a
representative in the upper half plane.
All computations are done with ``prec``
bits of precision. If ``prec`` is not given, use the precision of `z`.
EXAMPLES::
sage: E = EllipticCurve('37a')
sage: phi = E.modular_parametrization()
sage: phi((sqrt(7)*I - 17)/74, 53)
(...e-16 - ...e-16*I : ...e-16 + ...e-16*I : 1.00000000000000)
Verify that the mapping is invariant under the action of `\Gamma_0(N)`
on the upper half plane::
sage: E = EllipticCurve('11a')
sage: phi = E.modular_parametrization()
sage: tau = CC((1+1j)/5)
sage: phi(tau)
(-3.92181329652811 - 12.2578555525366*I : 44.9649874434872 + 14.3257120944681*I : 1.00000000000000)
sage: phi(tau+1)
(-3.92181329652810 - 12.2578555525366*I : 44.9649874434872 + 14.3257120944681*I : 1.00000000000000)
sage: phi((6*tau+1) / (11*tau+2))
(-3.9218132965285... - 12.2578555525369*I : 44.964987443489... + 14.325712094467...*I : 1.00000000000000)
We can also apply the modular parametrization to a Heegner point on `X_0(N)`::
sage: H = heegner_points(389,-7,5); H
All Heegner points of conductor 5 on X_0(389) associated to QQ[sqrt(-7)]
sage: x = H[0]; x
Heegner point 5/778*sqrt(-7) - 147/778 of discriminant -7 and conductor 5 on X_0(389)
sage: E = EllipticCurve('389a'); phi = E.modular_parametrization()
sage: phi(x)
Heegner point of discriminant -7 and conductor 5 on elliptic curve of conductor 389
sage: phi(x).quadratic_form()
389*x^2 + 147*x*y + 14*y^2
ALGORITHM:
Integrate the modular form attached to this elliptic curve from
`z` to `\infty` to get a point on the lattice representation of
`E`, then use the Weierstrass `\wp` function to map it to the
curve itself.
"""
if isinstance(z, heegner.HeegnerPointOnX0N):
return z.map_to_curve(self.curve())
# Map to the CC of CC/PeriodLattice.
tm = verbose("Evaluating modular parameterization to precision %s bits" % prec)
w = self.map_to_complex_numbers(z, prec=prec)
# Map to E via Weierstrass P
z = self._E.elliptic_exponential(w)
verbose("Finished evaluating modular parameterization", tm)
return z
def modS_relations(syms):
"""
Compute quotient of Manin symbols by the S relations.
Here S is the 2x2 matrix [0, -1; 1, 0].
INPUT:
- ``syms`` - manin_symbols.ManinSymbols
OUTPUT:
- ``rels`` - set of pairs of pairs (j, s), where if
mod[i] = (j,s), then x_i = s\*x_j (mod S relations)
EXAMPLES::
sage: from sage.modular.modsym.manin_symbols import ManinSymbolList_gamma0
sage: from sage.modular.modsym.relation_matrix import modS_relations
::
sage: syms = ManinSymbolList_gamma0(2, 4); syms
Manin Symbol List of weight 4 for Gamma0(2)
sage: modS_relations(syms)
set([((3, -1), (4, 1)), ((5, -1), (5, 1)), ((1, 1), (6, 1)), ((0, 1), (7, 1)), ((3, 1), (4, -1)), ((2, 1), (8, 1))])
::
sage: syms = ManinSymbolList_gamma0(7, 2); syms
Manin Symbol List of weight 2 for Gamma0(7)
sage: modS_relations(syms)
set([((3, 1), (4, 1)), ((2, 1), (7, 1)), ((5, 1), (6, 1)), ((0, 1), (1, 1))])
Next we do an example with Gamma1::
sage: from sage.modular.modsym.manin_symbols import ManinSymbolList_gamma1
sage: syms = ManinSymbolList_gamma1(3,2); syms
Manin Symbol List of weight 2 for Gamma1(3)
sage: modS_relations(syms)
set([((3, 1), (6, 1)), ((0, 1), (5, 1)), ((0, 1), (2, 1)), ((3, 1), (4, 1)), ((6, 1), (7, 1)), ((1, 1), (2, 1)), ((1, 1), (5, 1)), ((4, 1), (7, 1))])
"""
if not isinstance(syms, manin_symbols.ManinSymbolList):
raise TypeError, "syms must be a ManinSymbolList"
tm = misc.verbose()
# We will fill in this set with the relations x_i + s*x_j = 0,
# where the notation is as in _sparse_2term_quotient.
rels = set()
for i in xrange(len(syms)):
j, s = syms.apply_S(i)
assert j != -1
if i < j:
rels.add( ((i,1),(j,s)) )
else:
rels.add( ((j,s),(i,1)) )
misc.verbose("finished creating S relations",tm)
return rels
def upper_bound_on_elliptic_factors(self, p=None, ellmax=2):
r"""
Return an upper bound (provably correct) on the number of
elliptic curves of conductor equal to the level of this
supersingular module.
INPUT:
- ``p`` - (default: 997) prime to work modulo
ALGORITHM: Currently we only use `T_2`. Function will be
extended to use more Hecke operators later.
The prime p is replaced by the smallest prime that doesn't
divide the level.
EXAMPLES::
sage: SupersingularModule(37).upper_bound_on_elliptic_factors()
2
(There are 4 elliptic curves of conductor 37, but only 2 isogeny
classes.)
"""
# NOTE: The heuristic runtime is *very* roughly `p^2/(2\cdot 10^6)`.
#ellmax -- (default: 2) use Hecke operators T_ell with ell <= ellmax
if p is None:
p = 997
while self.level() % p == 0:
p = next_prime(p)
ell = 2
t = self.hecke_matrix(ell).change_ring(rings.GF(p))
# TODO: temporarily try using sparse=False
# turn this off when sparse rank is optimized.
t = t.dense_matrix()
B = 2 * math.sqrt(ell)
bnd = 0
lower = -int(math.floor(B))
upper = int(math.floor(B)) + 1
for a in range(lower, upper):
tm = verbose("computing T_%s - %s" % (ell, a))
if a == lower:
c = a
else:
c = 1
for i in range(t.nrows()):
t[i, i] += c
tm = verbose("computing kernel", tm)
#dim = t.kernel().dimension()
dim = t.nrows() - t.rank()
bnd += dim
verbose('got dimension = %s; new bound = %s' % (dim, bnd), tm)
return bnd
def upper_bound_on_elliptic_factors(self, p=None, ellmax=2):
r"""
Return an upper bound (provably correct) on the number of
elliptic curves of conductor equal to the level of this
supersingular module.
INPUT:
- ``p`` - (default: 997) prime to work modulo
ALGORITHM: Currently we only use `T_2`. Function will be
extended to use more Hecke operators later.
The prime p is replaced by the smallest prime that doesn't
divide the level.
EXAMPLE::
sage: SupersingularModule(37).upper_bound_on_elliptic_factors()
2
(There are 4 elliptic curves of conductor 37, but only 2 isogeny
classes.)
"""
# NOTE: The heuristic runtime is *very* roughly `p^2/(2\cdot 10^6)`.
# ellmax -- (default: 2) use Hecke operators T_ell with ell <= ellmax
if p is None:
p = 997
while self.level() % p == 0:
p = rings.next_prime(p)
ell = 2
t = self.hecke_matrix(ell).change_ring(rings.GF(p))
# TODO: temporarily try using sparse=False
# turn this off when sparse rank is optimized.
t = t.dense_matrix()
B = 2 * math.sqrt(ell)
bnd = 0
lower = -int(math.floor(B))
upper = int(math.floor(B)) + 1
for a in range(lower, upper):
tm = verbose("computing T_%s - %s" % (ell, a))
if a == lower:
c = a
else:
c = 1
for i in range(t.nrows()):
t[i, i] += c
tm = verbose("computing kernel", tm)
# dim = t.kernel().dimension()
dim = t.nrows() - t.rank()
bnd += dim
verbose("got dimension = %s; new bound = %s" % (dim, bnd), tm)
return bnd
def double_det (A, b, c, proof):
"""
Compute the determinants of the stacked integer matrices
A.stack(b) and A.stack(c).
INPUT:
- A -- an (n-1) x n matrix
- b -- an 1 x n matrix
- c -- an 1 x n matrix
- proof -- whether or not to compute the det modulo enough times to
provably compute the determinant.
OUTPUT:
- a pair of two integers.
EXAMPLES::
sage: from sage.matrix.matrix_integer_dense_hnf import double_det
sage: A = matrix(ZZ, 2, 3, [1,2,3, 4,-2,5])
sage: b = matrix(ZZ, 1, 3, [1,-2,5])
sage: c = matrix(ZZ, 1, 3, [8,2,10])
sage: A.stack(b).det()
-48
sage: A.stack(c).det()
42
sage: double_det(A, b, c, False)
(-48, 42)
"""
# We use the "two for the price of one" algorithm, which I made up. (William Stein)
# This is a clever trick! First we transpose everything. Then
# we use that if [A|b]*v = c then [A|c]*w = b with w easy to write down!
# In fact w is got from v by dividing all entries by -v[n], where n is the
# number of rows of v, and *also* dividing the last entry of w by v[n] again.
# See this as an algebra exercise where you have to think of matrix vector
# multiply as "linear combination of columns".
A = A.transpose()
b = b.transpose()
c = c.transpose()
t = verbose('starting double det')
B = A.augment(b)
v = B.solve_right(-c)
db = det_given_divisor(B, v.denominator(), proof=proof)
n = v.nrows()
vn = v[n-1,0]
w = (-1/vn)*v
w[n-1] = w[n-1]/vn
dc = det_given_divisor(A.augment(c), w.denominator(), proof=proof)
verbose('finished double det', t)
return (db, dc)
def double_det(A, b, c, proof):
"""
Compute the determinants of the stacked integer matrices
A.stack(b) and A.stack(c).
INPUT:
- A -- an (n-1) x n matrix
- b -- an 1 x n matrix
- c -- an 1 x n matrix
- proof -- whether or not to compute the det modulo enough times to
provably compute the determinant.
OUTPUT:
- a pair of two integers.
EXAMPLES::
sage: from sage.matrix.matrix_integer_dense_hnf import double_det
sage: A = matrix(ZZ, 2, 3, [1,2,3, 4,-2,5])
sage: b = matrix(ZZ, 1, 3, [1,-2,5])
sage: c = matrix(ZZ, 1, 3, [8,2,10])
sage: A.stack(b).det()
-48
sage: A.stack(c).det()
42
sage: double_det(A, b, c, False)
(-48, 42)
"""
# We use the "two for the price of one" algorithm, which I made up. (William Stein)
# This is a clever trick! First we transpose everything. Then
# we use that if [A|b]*v = c then [A|c]*w = b with w easy to write down!
# In fact w is got from v by dividing all entries by -v[n], where n is the
# number of rows of v, and *also* dividing the last entry of w by v[n] again.
# See this as an algebra exercise where you have to think of matrix vector
# multiply as "linear combination of columns".
A = A.transpose()
b = b.transpose()
c = c.transpose()
t = verbose('starting double det')
B = A.augment(b)
v = B.solve_right(-c)
db = det_given_divisor(B, v.denominator(), proof=proof)
n = v.nrows()
vn = v[n - 1, 0]
w = (-1 / vn) * v
w[n - 1] = w[n - 1] / vn
dc = det_given_divisor(A.augment(c), w.denominator(), proof=proof)
verbose('finished double det', t)
return (db, dc)
def _lift_to_OMS(self, p, M, new_base_ring, check):
"""
Returns a (`p`-adic) overconvergent modular symbol with `M` moments which lifts self up to an Eisenstein error
Here the Eisenstein error is a symbol whose system of Hecke eigenvalues equals `ell+1` for `T_ell` when `ell`
does not divide `Np` and 1 for `U_q` when `q` divides `Np`.
INPUT:
- ``p`` -- prime
- ``M`` -- integer equal to the number of moments
- ``new_base_ring`` -- new base ring
OUTPUT:
- An overconvergent modular symbol whose specialization equals self up to some Eisenstein error.
EXAMPLES::
"""
D = {}
manin = self.parent().source()
MSS = self.parent()._lift_parent_space(p, M, new_base_ring)
verbose("Naive lifting: newM=%s, new_base_ring=%s"%(M, MSS.base_ring()))
half = ZZ(1) / ZZ(2)
for g in manin.gens()[1:]:
twotor = g in manin.reps_with_two_torsion
threetor = g in manin.reps_with_three_torsion
if twotor:
# See [PS] section 4.1
gam = manin.two_torsion[g]
mu = self._map[g].lift(p, M, new_base_ring)
D[g] = (mu * gam - mu) * half
elif threetor:
# See [PS] section 4.1
gam = manin.three_torsion[g]
mu = self._map[g].lift(p, M, new_base_ring)
D[g] = (2 * mu - mu * gam - mu * (gam**2)) * half
else:
# no two or three torsion
D[g] = self._map[g].lift(p, M, new_base_ring)
t = self.parent().coefficient_module().lift(p, M, new_base_ring).zero_element()
for h in manin[2:]:
R = manin.relations(h)
if len(R) == 1:
c, A, g = R[0]
if c == 1:
t += self._map[h].lift(p, M, new_base_ring)
elif A is not Id:
# rules out extra three torsion terms
t += c * self._map[g].lift(p, M, new_base_ring) * A
D[manin.gen(0)] = t.solve_diff_eqn() ###### Check this!
return MSS(D)
def p_saturation(A, p, proof=True):
"""
INPUT:
- A -- a matrix over ZZ
- p -- a prime
- proof -- bool (default: True)
OUTPUT:
The p-saturation of the matrix A, i.e., a new matrix in Hermite form
whose row span a ZZ-module that is p-saturated.
EXAMPLES::
sage: from sage.matrix.matrix_integer_dense_saturation import p_saturation
sage: A = matrix(ZZ, 2, 2, [3,2,3,4]); B = matrix(ZZ, 2,3,[1,2,3,4,5,6])
sage: A.det()
6
sage: C = A*B; C
[11 16 21]
[19 26 33]
sage: C2 = p_saturation(C, 2); C2
[ 1 8 15]
[ 0 9 18]
sage: C2.index_in_saturation()
9
sage: C3 = p_saturation(C, 3); C3
[ 1 0 -1]
[ 0 2 4]
sage: C3.index_in_saturation()
2
"""
tm = verbose("%s-saturating a %sx%s matrix"%(p, A.nrows(), A.ncols()))
H = A.hermite_form(include_zero_rows=False, proof=proof)
while True:
if p == 2:
A = H.change_ring(GF(p))
else:
try:
# Faster than change_ring
A = H._reduce(p)
except OverflowError:
# fall back to generic GF(p) matrices
A = H.change_ring(GF(p))
assert A.nrows() <= A.ncols()
K = A.kernel()
if K.dimension() == 0:
verbose("done saturating", tm)
return H
B = K.basis_matrix().lift()
C = ((B * H) / p).change_ring(ZZ)
H = H.stack(C).hermite_form(include_zero_rows=False, proof=proof)
verbose("done saturating", tm)
def p_saturation(A, p, proof=True):
"""
INPUT:
- A -- a matrix over ZZ
- p -- a prime
- proof -- bool (default: True)
OUTPUT:
The p-saturation of the matrix A, i.e., a new matrix in Hermite form
whose row span a ZZ-module that is p-saturated.
EXAMPLES::
sage: from sage.matrix.matrix_integer_dense_saturation import p_saturation
sage: A = matrix(ZZ, 2, 2, [3,2,3,4]); B = matrix(ZZ, 2,3,[1,2,3,4,5,6])
sage: A.det()
6
sage: C = A*B; C
[11 16 21]
[19 26 33]
sage: C2 = p_saturation(C, 2); C2
[ 1 8 15]
[ 0 9 18]
sage: C2.index_in_saturation()
9
sage: C3 = p_saturation(C, 3); C3
[ 1 0 -1]
[ 0 2 4]
sage: C3.index_in_saturation()
2
"""
tm = verbose("%s-saturating a %sx%s matrix" % (p, A.nrows(), A.ncols()))
H = A.hermite_form(include_zero_rows=False, proof=proof)
while True:
if p == 2:
A = H.change_ring(GF(p))
else:
try:
# Faster than change_ring
A = H._reduce(p)
except OverflowError:
# fall back to generic GF(p) matrices
A = H.change_ring(GF(p))
assert A.nrows() <= A.ncols()
K = A.kernel()
if K.dimension() == 0:
verbose("done saturating", tm)
return H
B = K.basis_matrix().lift()
C = ((B * H) / p).change_ring(ZZ)
H = H.stack(C).hermite_form(include_zero_rows=False, proof=proof)
verbose("done saturating", tm)
def _find_extraprec(self, p, M, alpha, check):
q, aq, eisenloss = self._find_aq(p, M, check)
newM = M + eisenloss
# We also need to add precision to account for denominators appearing while solving the difference equation.
eplog = (newM -1).exact_log(p)
while eplog < (newM + eplog).exact_log(p):
eplog = (newM + eplog).exact_log(p)
verbose("M = %s, newM = %s, eplog=%s"%(M, newM, eplog), level=2)
newM += eplog
return newM, eisenloss, q, aq
def det_from_modp_and_divisor(A,
d,
p,
z_mod,
moduli,
z_so_far=ZZ(1),
N_so_far=ZZ(1)):
"""
This is used for internal purposes for computing determinants
quickly (with the hybrid p-adic / multimodular algorithm).
INPUT:
- A -- a square matrix
- d -- a divisor of the determinant of A
- p -- a prime
- z_mod -- values of det/d (mod ...)
- moduli -- the moduli so far
- z_so_far -- for a modulus p in the list moduli,
(z_so_far mod p) is the determinant of A modulo p.
- N_so_far -- N_so_far is the product over the primes in the list moduli.
OUTPUT:
- A triple (det bound, new z_so_far, new N_so_far).
EXAMPLES::
sage: a = matrix(ZZ, 3, [6, 1, 2, -56, -2, -1, -11, 2, -3])
sage: factor(a.det())
-1 * 13 * 29
sage: d = 13
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.det_from_modp_and_divisor(a, d, 97, [], [])
(-377, -29, 97)
sage: a.det()
-377
"""
tm = verbose("Multimodular stage of det calculation -- using p = %s" % p,
level=2)
z = A.mod(p).det() / d
z = z.lift()
z_mod.append(z)
moduli.append(p)
z = CRT_list([z_so_far, z], [N_so_far, p])
N = N_so_far * p
if z > N // 2:
z -= N
verbose("Finished multimodular det for p = %s" % p, tm, level=2)
return (d * z, z, N)
def multiply_forms_to_weight(forms, weight, stop_dim=None):
r"""
Given a list of pairs ``(k,f)``, where `k` is an integer and `f` is a power
series, and a weight l, return all weight l forms obtained by multiplying
together the given forms.
INPUT:
- forms -- list of pairs (k, f) with k an integer and f a power series
- weight -- an integer
- stop_dim -- integer (optional): if set to an integer and we find that the
series so far span a space of at least this dimension, then stop
multiplying more forms together.
EXAMPLES::
sage: import sage.modular.modform.find_generators as f
sage: forms = [(4, 240*eisenstein_series_qexp(4,5)), (6,504*eisenstein_series_qexp(6,5))]
sage: f.multiply_forms_to_weight(forms, 12)
[(12, 1 - 1008*q + 220752*q^2 + 16519104*q^3 + 399517776*q^4 + O(q^5)), (12, 1 + 720*q + 179280*q^2 + 16954560*q^3 + 396974160*q^4 + O(q^5))]
sage: f.multiply_forms_to_weight(forms, 24)
[(24, 1 - 2016*q + 1457568*q^2 - 411997824*q^3 + 16227967392*q^4 + O(q^5)), (24, 1 - 288*q - 325728*q^2 + 11700864*q^3 + 35176468896*q^4 + O(q^5)), (24, 1 + 1440*q + 876960*q^2 + 292072320*q^3 + 57349833120*q^4 + O(q^5))]
sage: dimension_modular_forms(SL2Z,24)
3
"""
verbose('multiplying forms up to weight %s'%weight)
# Algorithm: run through the subsets of forms and for each check
# whether or not the sum of the weights (with coefficients -- i.e.,
# account for multiplicities) of the forms equals weight.
# If so, multiply those together and append them to the output
# list v
# The answer list
v = []
n = len(forms)
# List of weights
from sage.combinat.integer_vector_weighted import WeightedIntegerVectors
wts = WeightedIntegerVectors(weight, [f[0] for f in forms])
for c in wts:
if sum(c[i]*forms[i][0] for i in xrange(n) if c[i]) != weight:
raise ArithmeticError, "Can't get here!"
g = prod(forms[i][1]**c[i] for i in xrange(n))
v.append((weight, g))
if stop_dim and len(v) >= stop_dim:
z = span_of_series([f for _, f in v]).dimension()
if z >= stop_dim:
return v
return v
def first_solvable_system(Q, min_step=None):
r"""
Return the matrix in the lowest step such that there exists a nontrivial
abnormal covector admitting the factor Q.
INPUT:
- ``Q`` -- a polynomial to search for as an abnormal factor
- ``min_step`` -- the lowest nilpotency step to check for solutions
OUTPUT:
A pair (params, A), where
- ``params`` -- a tuple (L,m,s) of data related to the matrix A
- ``A`` -- the matrix of the first solvable system
The parameters are
- ``L`` -- the free Lie algebra quotient
- ``m`` -- the lowest degree of covectors in the system
- ``s`` -- the nilpotency step where a solution is found
"""
PR = Q.parent()
weights = PR.term_order().weights()
r = weights.count(1)
m = max(weights) + 1
s = m + Q.degree()
if min_step is not None:
s = max(min_step, s)
R = PR.base_ring()
L = NotAFreeLieAlgebra(R, ['X_%d' % (k + 1) for k in range(r)])
L = L.HallQuotient(m)
systems = {}
while True:
verbose("searching for solutions in step %d" % s)
A = abnormal_factor_system(L, Q, r, m, s, homogeneous=False)
systems[s] = A
if A.rank() < len(A.columns()):
verbose("first solution exists in step %d" % s)
break
s += 1
return (L, m, s), A
def add_column(B, H_B, a, proof):
"""
The add column procedure.
INPUT:
- B -- a square matrix (may be singular)
- H_B -- the Hermite normal form of B
- a -- an n x 1 matrix, where B has n rows
- proof -- bool; whether to prove result correct, in case we use fallback method.
OUTPUT:
- x -- a vector such that H' = H_B.augment(x) is the HNF of A = B.augment(a).
EXAMPLES::
sage: B = matrix(ZZ, 3, 3, [1,2,5, 0,-5,3, 1,1,2])
sage: H_B = B.echelon_form()
sage: a = matrix(ZZ, 3, 1, [1,8,-2])
sage: import sage.matrix.matrix_integer_dense_hnf as hnf
sage: x = hnf.add_column(B, H_B, a, True); x
[18]
[ 3]
[23]
sage: H_B.augment(x)
[ 1 0 17 18]
[ 0 1 3 3]
[ 0 0 18 23]
sage: B.augment(a).echelon_form()
[ 1 0 17 18]
[ 0 1 3 3]
[ 0 0 18 23]
"""
verbose('starting add_column')
if B.rank() < B.nrows():
return add_column_fallback(B, a, proof)
else:
z = solve_system_with_difficult_last_row(B, a)
zd, d = z._clear_denom()
x = H_B * zd
if d != 1:
for i in range(x.nrows()):
x[i, 0] = x[i, 0] / d
return x
def _lmul_(self, right):
"""
Scalar multiplication self*right.
"""
#RH: mostly "copied" from dist.pyx but then changed
ans = CoeffMod_OMS_element(None, self.parent(), None, False)
#p = self.parent().prime()
if right.is_zero():
verbose("right is zero: %s"%(right), level=2)
ans._moments = self.parent().approx_module(0)([])
ans.ordp = min(self.parent().precision_cap(), right.valuation()+self.ordp)
else:
v, u = right.val_unit()
ans._moments = self._moments * u
ans.ordp = self.ordp + v
return ans
def hnf_square(A, proof):
"""
INPUT:
a nonsingular n x n matrix A over the integers.
OUTPUT:
the Hermite normal form of A.
EXAMPLES:
sage: import sage.matrix.matrix_integer_dense_hnf as hnf
sage: A = matrix(ZZ, 3, [-21, -7, 5, 1,20,-7, -1,1,-1])
sage: hnf.hnf_square(A, False)
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
sage: A.echelon_form()
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
"""
n = A.nrows()
m = A.ncols()
if n != m:
raise ValueError("A must be square.")
# Small cases -- don't use this algorithm
if n <= 3:
return A.echelon_form(algorithm="pari")
if A.rank() < A.nrows():
raise ValueError("matrix must have full rank")
t = verbose("starting slicings")
B = A.matrix_from_rows(range(m-2)).matrix_from_columns(range(n-1))
c = A.matrix_from_rows([m-2]).matrix_from_columns (range(n-1))
d = A.matrix_from_rows([m-1]).matrix_from_columns (range(n-1))
b = A.matrix_from_columns([n-1]).matrix_from_rows(range(m-2))
verbose("done slicing", t)
try:
(d1,d2) = double_det (B,c,d, proof=proof)
except (ValueError, ZeroDivisionError), msg:
d1 = B.stack(c).det(proof=proof)
d2 = B.stack(d).det(proof=proof)
def abnormal_polynomials(L, r, m, s):
r"""
Return the highest degree coefficients for abnormal polynomials in step `s`
of layer `m` in the Lie algebra `L`.
INPUT:
- ``L`` -- the Lie algebra to do the computations in
- ``r`` -- the rank of the free Lie algebra
- ``m`` -- the layer whose abnormal polynomials are computed
- ``s`` -- the step of coefficients to compute
OUTPUT:
A dictionary {X: {mon: coeff}, where
- ``X`` -- a Hall basis element of layer `m`
- ``mon`` -- a tuple `(i_1,...,i_n)` describing the monomial
`x_1^{i_1}...x_n^{i_n}`
- ``coeff`` -- an element of a :class:`HallQuotient` Lie algebra whose dual
element would be the coefficient of the monomial in the polynomial `P_X`
"""
elems = sum((list(L.graded_basis(k)) for k in range(1, m)), [])
weights = sum(([k] * len(L.graded_basis(k)) for k in range(1, m)), [])
P = {}
mons = list(reversed(list(WeightedIntegerVectors(s - m, weights))))
verbose("computing abnormal polynomials:")
for X in L.graded_basis(m):
PX = {}
pname = freebasis_element_to_short_word(X).replace("X", "P")
verbose(" %s deg %d coefficients" % (pname, s - m))
# compute coefficients for the abnormal polynomial P_X
for mon in mons:
# compute coefficient of the monomial mon
adx = X
mult = QQ(1)
for i in mon:
mult = mult / factorial(i)
for rep, Xi in zip(mon, elems):
for k in range(rep):
adx = Xi.bracket(adx)
PX[tuple(mon)] = mult * adx
P[X] = PX
return P
def hnf_square(A, proof):
"""
INPUT:
a nonsingular n x n matrix A over the integers.
OUTPUT:
the Hermite normal form of A.
EXAMPLES:
sage: import sage.matrix.matrix_integer_dense_hnf as hnf
sage: A = matrix(ZZ, 3, [-21, -7, 5, 1,20,-7, -1,1,-1])
sage: hnf.hnf_square(A, False)
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
sage: A.echelon_form()
[ 1 6 29]
[ 0 7 28]
[ 0 0 46]
"""
n = A.nrows()
m = A.ncols()
if n != m:
raise ValueError("A must be square.")
# Small cases -- don't use this algorithm
if n <= 3:
return A.echelon_form(algorithm="pari")
if A.rank() < A.nrows():
raise ValueError("matrix must have full rank")
t = verbose("starting slicings")
B = A.matrix_from_rows(range(m-2)).matrix_from_columns(range(n-1))
c = A.matrix_from_rows([m-2]).matrix_from_columns (range(n-1))
d = A.matrix_from_rows([m-1]).matrix_from_columns (range(n-1))
b = A.matrix_from_columns([n-1]).matrix_from_rows(range(m-2))
verbose("done slicing", t)
try:
(d1,d2) = double_det (B,c,d, proof=proof)
except (ValueError, ZeroDivisionError), msg:
d1 = B.stack(c).det(proof=proof)
d2 = B.stack(d).det(proof=proof)
def is_in_hnf_form(H, pivots):
"""
Return whether the matrix ``H`` is in Hermite normal form
with given pivot columns.
INPUT:
- ``H`` -- matrix
- ``pivots`` -- sorted list of integers
OUTPUT:
boolean
EXAMPLES::
sage: a = matrix(ZZ,3,5,[-2, -6, -3, -17, -1, 2, -1, -1, -2, -1, -2, -2, -6, 9, 2])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.is_in_hnf_form(a,range(3))
False
sage: e = a.hermite_form(); p = a.pivots()
sage: matrix_integer_dense_hnf.is_in_hnf_form(e, p)
True
"""
tt = verbose('testing if matrix is in HNF')
r = 0
pivots_set = set(pivots)
for j in range(H.ncols()):
if j in pivots_set:
for i in range(r + 1, H.nrows()):
if H[i, j]:
verbose('not HNF because nonzeros below pivot position',
tt)
return False
for i in range(r):
if H[i, j] < 0 or H[i, j] >= H[r, j]:
verbose(
'not HNF because negative or too big above pivot position',
tt)
return False
r += 1
else:
for i in range(r, H.nrows()):
if H[i, j]:
verbose(
'not HNF nonzero in wrong place in nonpivot column',
tt)
return False
verbose('done verifying in HNF -- yes', tt)
return True
def _discrete_exp(self, v):
r"""
Given a list (or other iterable) of length equal to the number of
generators of this group, compute the element of the ambient group with
those exponents in terms of the generators of self.
EXAMPLE::
sage: G = AdditiveAbelianGroupWrapper(QQbar, [sqrt(QQbar(2)), -1], [0, 0])
sage: v = G._discrete_exp([3, 5]); v
-0.7573593128807148?
sage: v.parent() is QQbar
True
"""
v = self.V()(v)
verbose("Calling discrete exp on %s" % v)
# DUMB IMPLEMENTATION!
return sum([self._gen_elements[i] * ZZ(v[i]) for i in xrange(len(v))], self.universe()(0))
def _discrete_exp(self, v):
r"""
Given a list (or other iterable) of length equal to the number of
generators of this group, compute the element of the ambient group with
those exponents in terms of the generators of self.
EXAMPLE::
sage: G = AdditiveAbelianGroupWrapper(QQbar, [sqrt(QQbar(2)), -1], [0, 0])
sage: v = G._discrete_exp([3, 5]); v
-0.7573593128807148?
sage: v.parent() is QQbar
True
"""
v = self.V()(v)
verbose("Calling discrete exp on %s" % v)
# DUMB IMPLEMENTATION!
return sum([self._gen_elements[i] * ZZ(v[i]) for i in xrange(len(v))], self.universe()(0))
def _find_extraprec(self, p, M, alpha, check):
eisenloss = (alpha - 1).valuation(p)
# Here we make a judgement that lifting to higher precision is cheaper than computing extra Hecke operators.
if eisenloss < M:
q = None
aq = None
else:
# ap = 1 (mod p^M), so we need to use other Hecke eigenvalues
q, aq, eisenloss = self._find_aq(p, M, check)
newM = M + eisenloss
# We also need to add precision to account for denominators appearing while solving the difference equation.
eplog = (newM -1).exact_log(p)
while eplog < (newM + eplog).exact_log(p):
eplog = (newM + eplog).exact_log(p)
verbose("M = %s, newM = %s, eplog=%s"%(M, newM, eplog), level=2)
newM += eplog
return newM, eisenloss, q, aq
def det_from_modp_and_divisor(A, d, p, z_mod, moduli, z_so_far=ZZ(1), N_so_far=ZZ(1)):
"""
This is used for internal purposes for computing determinants
quickly (with the hybrid p-adic / multimodular algorithm).
INPUT:
- A -- a square matrix
- d -- a divisor of the determinant of A
- p -- a prime
- z_mod -- values of det/d (mod ...)
- moduli -- the moduli so far
- z_so_far -- for a modulus p in the list moduli,
(z_so_far mod p) is the determinant of A modulo p.
- N_so_far -- N_so_far is the product over the primes in the list moduli.
OUTPUT:
- A triple (det bound, new z_so_far, new N_so_far).
EXAMPLES::
sage: a = matrix(ZZ, 3, [6, 1, 2, -56, -2, -1, -11, 2, -3])
sage: factor(a.det())
-1 * 13 * 29
sage: d = 13
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.det_from_modp_and_divisor(a, d, 97, [], [])
(-377, -29, 97)
sage: a.det()
-377
"""
tm = verbose("Multimodular stage of det calculation -- using p = %s"%p, level=2)
z = A.mod(p).det() / d
z = z.lift()
z_mod.append(z)
moduli.append(p)
z = CRT_list([z_so_far, z], [N_so_far, p])
N = N_so_far*p
if z > N//2:
z = z - N
verbose("Finished multimodular det for p = %s"%p, tm, level=2)
return (d * z, z, N)
def options(self):
"""
Return the dictionary of options for this graphics primitive.
By default this function verifies that the options are all
valid; if any aren't, then a verbose message is printed with level 0.
EXAMPLES::
sage: from sage.plot.primitive import GraphicPrimitive
sage: GraphicPrimitive({}).options()
{}
"""
from sage.plot.plot import do_verify
from sage.plot.colors import hue
O = dict(self.__options)
if do_verify:
A = self._allowed_options()
t = False
K = A.keys() + ['xmin', 'xmax', 'ymin', 'ymax', 'axes']
for k in O.keys():
if not k in K:
do_verify = False
verbose("WARNING: Ignoring option '%s'=%s" % (k, O[k]),
level=0)
t = True
if t:
s = "\nThe allowed options for %s are:\n" % self
K.sort()
for k in K:
if A.has_key(k):
s += " %-15s%-60s\n" % (k, A[k])
verbose(s, level=0)
if 'hue' in O:
t = O['hue']
if not isinstance(t, (tuple, list)):
t = [t, 1, 1]
O['rgbcolor'] = hue(*t)
del O['hue']
return O
def options(self):
"""
Return the dictionary of options for this graphics primitive.
By default this function verifies that the options are all
valid; if any aren't, then a verbose message is printed with level 0.
EXAMPLES::
sage: from sage.plot.primitive import GraphicPrimitive
sage: GraphicPrimitive({}).options()
{}
"""
from sage.plot.graphics import do_verify
from sage.plot.colors import hue
O = dict(self._options)
if do_verify:
A = self._allowed_options()
t = False
K = A.keys() + ['xmin', 'xmax', 'ymin', 'ymax', 'axes']
for k in O.keys():
if not k in K:
do_verify = False
verbose("WARNING: Ignoring option '%s'=%s"%(k,O[k]), level=0)
t = True
if t:
s = "\nThe allowed options for %s are:\n"%self
K.sort()
for k in K:
if A.has_key(k):
s += " %-15s%-60s\n"%(k,A[k])
verbose(s, level=0)
if 'hue' in O:
t = O['hue']
if not isinstance(t, (tuple,list)):
t = [t,1,1]
O['rgbcolor'] = hue(*t)
del O['hue']
return O
def _eval_line(self, line, allow_use_file=True, wait_for_prompt=True):
"""
EXAMPLES::
sage: gp._eval_line('2+2')
'4'
"""
line = line.strip()
if len(line) == 0:
return ''
a = Expect._eval_line(self, line,
allow_use_file=allow_use_file,
wait_for_prompt=wait_for_prompt)
if a.find("the PARI stack overflows") != -1:
verbose("automatically doubling the PARI stack and re-executing current input line")
b = self.eval("allocatemem()")
if b.find("Warning: not enough memory") != -1:
raise RuntimeError, a
return self._eval_line(line)
else:
return a
def _consistency_check(self):
"""
Check that the map really does satisfy the Manin relations loop (for debugging).
The two and three torsion relations are checked and it is checked that the symbol
adds up correctly around the fundamental domain
EXAMPLES::
sage: D = OverconvergentDistributions(0, 7, base=Qp(7,5))
sage: MS = OverconvergentModularSymbols(14, coefficients=D);
sage: MR = MS.source()
sage: V = D.approx_module()
sage: Phi_dict = {MR.gens()[0]:7 * V((5 + 6*7 + 7^2 + 4*7^3 + 5*7^4 + O(7^5), 6 + 5*7 + 2*7^2 + 3*7^3 + O(7^4), 4 + 5*7 + 7^2 + O(7^3), 2 + 7 + O(7^2), 4 + O(7))), MR.gens()[1]:7 * V((4 + 2*7 + 4*7^2 + 5*7^3 + O(7^5), 5 + 7^2 + 4*7^3 + O(7^4), 1 + 7 + 5*7^2 + O(7^3), 2 + O(7^2), 4 + O(7))), MR.gens()[2]:7 * V((3 + 6*7 + 6*7^2 + 5*7^3 + 7^4 + O(7^5), 6 + 5*7 + 5*7^3 + O(7^4), 3 + 6*7^2 + O(7^3), 6 + 2*7 + O(7^2), O(7))), MR.gens()[3]:7 * V((5 + 3*7 + 4*7^2 + 7^3 + 3*7^4 + O(7^5), 2 + 4*7^2 + 2*7^3 + O(7^4), 1 + 4*7 + 2*7^2 + O(7^3), 6*7 + O(7^2), 6 + O(7))), MR.gens()[4]:7 * V((3 + 2*7^2 + 3*7^3 + 3*7^4 + O(7^5), 5*7 + 4*7^2 + 2*7^3 + O(7^4), 6 + 4*7 + 2*7^2 + O(7^3), 2 + 3*7 + O(7^2), O(7)))}
sage: Phi = MS(Phi_dict)
sage: Phi._consistency_check()
This modular symbol satisfies the manin relations
"""
# sage: from sage.modular.pollack_stevens.space import ps_modsym_from_elliptic_curve
# sage: E = EllipticCurve('37a1')
# sage: phi = ps_modsym_from_elliptic_curve(E)
# sage: phi._consistency_check()
# This modular symbol satisfies the manin relations
f = self._map
MR = self._map._manin
## Test two torsion relations
for g in MR.reps_with_two_torsion():
gamg = MR.two_torsion_matrix(g)
if not (f[g]*gamg + f[g]).is_zero():
verbose("f[g]*gamg + f[g] equals: %s"%(f[g]*gamg + f[g]))
raise ValueError("Two torsion relation failed with",g)
## Test three torsion relations
for g in MR.reps_with_three_torsion():
gamg = MR.three_torsion_matrix(g)
if not (f[g]*(gamg**2) + f[g]*gamg + f[g]).is_zero():
verbose("f[g]*(gamg**2) + f[g]*gamg + f[g] equals: %s"%(f[g]*(gamg**2) + f[g]*gamg + f[g]))
raise ValueError("Three torsion relation failed with",g)
## Test that the symbol adds to 0 around the boundary of the fundamental domain
t = self.parent().coefficient_module().zero_element()
for g in MR.gens()[1:]:
if (not g in MR.reps_with_two_torsion()) and (not g in MR.reps_with_three_torsion()):
t += f[g] * MR.gammas[g] - f[g]
else:
if g in MR.reps_with_two_torsion():
t -= f[g]
else:
t -= f[g]
id = MR.gens()[0]
if f[id]*MR.gammas[id] - f[id] != -t:
print -t
print "------------"
print f[id]*MR.gammas[id] - f[id]
print "------------"
print f[id]*MR.gammas[id] - f[id]+t
verbose("Sum around loop is: %s"%(f[id]*MR.gammas[id] - f[id]+t))
raise ValueError("Does not add up correctly around loop")
print "This modular symbol satisfies the manin relations"
def basis_of_ordinary_subspace(self, d=None):
r"""
Finds a basis of the ordinary subspace of this space.
INPUT:
- ``d`` -- (optional) integer equal to the dimension of the ordinary subspace; otherwise this number is just computed via Hida theory
- ``sign`` -- optional variable which if 1 or -1 restricts to the plus or minus subspace
OUTPUT:
- A list of OMS's which form the desired basis
"""
if d is None:
d = self.dimension_of_ordinary_subspace()
basis = []
done = (d <= len(basis))
M = self.precision_cap()
p = self.prime()
while not done:
print "basis has size %s out of %s" % (len(basis), d)
verbose("Forming a random symbol")
print "-----------------------"
print "Forming a random symbol"
Phi = self.random_element()
verbose("Projecting to ordinary subspace")
print "projecting"
for a in range(M + 2):
print a
Phi = Phi.hecke(p)
## Should really check here that we are ordinary
verbose("Forming U_p-span of this symbol")
print "Forming U_p-span"
Phi_span = [Phi]
LI = self.is_start_of_basis(Phi_span)
if LI and self.is_start_of_basis(basis + [Phi_span[-1]]):
basis += [Phi_span[-1]]
verbose("basis now has size %s" % (len(basis)))
done = (d <= len(basis))
while LI and (not done):
Phi_span += [Phi_span[-1].hecke(p)]
LI = self.is_start_of_basis(Phi_span)
if LI and self.is_start_of_basis(basis + [Phi_span[-1]]):
basis += [Phi_span[-1]]
done = (d <= len(basis))
return basis
def _eval_line(self, line, reformat=True, allow_use_file=False,
wait_for_prompt=True, restart_if_needed=False):
"""
EXAMPLES::
sage: print(octave._eval_line('2+2')) #optional - octave
ans = 4
"""
from pexpect.exceptions import EOF
if not wait_for_prompt:
return Expect._eval_line(self, line)
if line == '':
return ''
if self._expect is None:
self._start()
if allow_use_file and len(line)>3000:
return self._eval_line_using_file(line)
try:
E = self._expect
# debug
# self._synchronize(cmd='1+%s\n')
verbose("in = '%s'"%line,level=3)
E.sendline(line)
E.expect(self._prompt)
out = bytes_to_str(E.before)
# debug
verbose("out = '%s'"%out,level=3)
except EOF:
if self._quit_string() in line:
return ''
except KeyboardInterrupt:
self._keyboard_interrupt()
try:
if reformat:
if 'syntax error' in out:
raise SyntaxError(out)
out = "\n".join(out.splitlines()[1:])
return out
except NameError:
return ''
def _next_var_name(self):
"""
Return the name of the next unused interface variable name.
EXAMPLES::
sage: g = Gp()
sage: g._next_var_name()
'sage[1]'
sage: g(2)^2
4
sage: g._next_var_name()
'sage[5]'
TESTS:
The vector of results is correctly resized when the stack has
to be enlarged during this operation::
sage: g = Gp(stacksize=10^4,init_list_length=12000) # long time
sage: for n in [1..13000]: # long time
....: a = g(n) # long time
sage: g('length(sage)') # long time
24000
"""
self.__seq += 1
if self.__seq >= self.__var_store_len:
if self.__var_store_len == 0:
self.eval('sage=vector(%s,k,0);' % self.__init_list_length)
self.__var_store_len = self.__init_list_length
else:
self.eval('sage0=concat(sage, vector(%s,k,0));' %
self.__var_store_len)
self.eval('sage=sage0;')
self.eval('kill(sage0);')
self.__var_store_len *= 2
verbose("doubling PARI/sage object vector: %s" %
self.__var_store_len)
return 'sage[%s]' % self.__seq
def is_in_hnf_form(H, pivots):
"""
Return True precisely if the matrix H is in Hermite normal form
with given pivot columns.
INPUT:
H -- matrix
pivots -- sorted list of integers
OUTPUT:
bool -- True or False
EXAMPLES::
sage: a = matrix(ZZ,3,5,[-2, -6, -3, -17, -1, 2, -1, -1, -2, -1, -2, -2, -6, 9, 2])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.is_in_hnf_form(a,range(3))
False
sage: e = a.hermite_form(); p = a.pivots()
sage: matrix_integer_dense_hnf.is_in_hnf_form(e, p)
True
"""
tt = verbose('testing if matrix is in HNF')
r = 0
pivots_set = set(pivots)
for j in xrange(H.ncols()):
if j in pivots_set:
for i in xrange(r+1, H.nrows()):
if H[i,j]:
verbose('not HNF because nonzeros below pivot position',tt)
return False
for i in xrange(r):
if H[i,j] < 0 or H[i,j] >= H[r,j]:
verbose('not HNF because negative or too big above pivot position',tt)
return False
r += 1
else:
for i in xrange(r,H.nrows()):
if H[i,j]:
verbose('not HNF nonzero in wrong place in nonpivot column',tt)
return False
verbose('done verifying in HNF -- yes', tt)
return True
def _next_var_name(self):
"""
EXAMPLES::
sage: g = Gp()
sage: g._next_var_name()
'sage[1]'
sage: g(2)^2
4
sage: g._next_var_name()
'sage[5]'
"""
self.__seq += 1
if self.__seq >= self.__var_store_len:
if self.__var_store_len == 0:
self.eval('sage=vector(%s,k,0);'%self.__init_list_length)
self.__var_store_len = self.__init_list_length
else:
self.eval('sage=concat(sage, vector(%s,k,0));'%self.__var_store_len)
self.__var_store_len *= 2
verbose("doubling PARI/sage object vector: %s"%self.__var_store_len)
return 'sage[%s]'%self.__seq
def add_column_fallback(B, a, proof):
"""
Simplistic version of add_column, in case the powerful clever one
fails (e.g., B is singular).
INPUT:
B -- a square matrix (may be singular)
a -- an n x 1 matrix, where B has n rows
proof -- bool; whether to prove result correct
OUTPUT:
x -- a vector such that H' = H_B.augment(x) is the HNF of A = B.augment(a).
EXAMPLES::
sage: B = matrix(ZZ,3, [-1, -1, 1, -3, 8, -2, -1, -1, -1])
sage: a = matrix(ZZ,3,1, [1,2,3])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.add_column_fallback(B, a, True)
[-3]
[-7]
[-2]
sage: matrix_integer_dense_hnf.add_column_fallback(B, a, False)
[-3]
[-7]
[-2]
sage: B.augment(a).hermite_form()
[ 1 1 1 -3]
[ 0 11 1 -7]
[ 0 0 2 -2]
"""
tt = verbose('add column fallback...')
W = B.augment(matrix(ZZ, B.nrows(), a.list()))
H, _ = hnf(W, proof)
C = H.matrix_from_columns([H.ncols() - 1])
verbose('finished add column fallback', tt)
return C
def add_column_fallback(B, a, proof):
"""
Simplistic version of add_column, in case the powerful clever one
fails (e.g., B is singular).
INPUT:
B -- a square matrix (may be singular)
a -- an n x 1 matrix, where B has n rows
proof -- bool; whether to prove result correct
OUTPUT:
x -- a vector such that H' = H_B.augment(x) is the HNF of A = B.augment(a).
EXAMPLES::
sage: B = matrix(ZZ,3, [-1, -1, 1, -3, 8, -2, -1, -1, -1])
sage: a = matrix(ZZ,3,1, [1,2,3])
sage: import sage.matrix.matrix_integer_dense_hnf as matrix_integer_dense_hnf
sage: matrix_integer_dense_hnf.add_column_fallback(B, a, True)
[-3]
[-7]
[-2]
sage: matrix_integer_dense_hnf.add_column_fallback(B, a, False)
[-3]
[-7]
[-2]
sage: B.augment(a).hermite_form()
[ 1 1 1 -3]
[ 0 11 1 -7]
[ 0 0 2 -2]
"""
tt = verbose('add column fallback...')
W = B.augment(matrix(ZZ,B.nrows(),a.list()))
H, _ = hnf(W, proof)
C = H.matrix_from_columns([H.ncols()-1])
verbose('finished add column fallback', tt)
return C
def modI_relations(syms, sign):
"""
Compute quotient of Manin symbols by the I relations.
INPUT:
- ``syms`` - ManinSymbols
- ``sign`` - int (either -1, 0, or 1)
OUTPUT:
- ``rels`` - set of pairs of pairs (j, s), where if
mod[i] = (j,s), then x_i = s\*x_j (mod S relations)
EXAMPLE::
sage: L = sage.modular.modsym.manin_symbols.ManinSymbolList_gamma1(4, 3)
sage: sage.modular.modsym.relation_matrix.modI_relations(L, 1)
set([((14, 1), (20, 1)), ((0, 1), (0, -1)), ((7, 1), (7, -1)), ((9, 1), (3, -1)), ((3, 1), (9, -1)), ((16, 1), (22, 1)), ((10, 1), (4, -1)), ((1, 1), (1, -1)), ((19, 1), (19, 1)), ((8, 1), (2, -1)), ((12, 1), (12, 1)), ((20, 1), (14, 1)), ((21, 1), (15, 1)), ((5, 1), (11, -1)), ((15, 1), (21, 1)), ((22, 1), (16, 1)), ((6, 1), (6, -1)), ((2, 1), (8, -1)), ((17, 1), (23, 1)), ((4, 1), (10, -1)), ((18, 1), (18, 1)), ((11, 1), (5, -1)), ((23, 1), (17, 1)), ((13, 1), (13, 1))])
.. warning::
We quotient by the involution eta((u,v)) = (-u,v), which has
the opposite sign as the involution in Merel's Springer LNM
1585 paper! Thus our +1 eigenspace is his -1 eigenspace,
etc. We do this for consistency with MAGMA.
"""
tm = misc.verbose()
# We will fill in this set with the relations x_i - sign*s*x_j = 0,
# where the notation is as in _sparse_2term_quotient.
rels = set()
for i in xrange(len(syms)):
j, s = syms.apply_I(i)
assert j != -1
rels.add( ((i,1),(j,-sign*s)) )
misc.verbose("finished creating I relations",tm)
return rels
def zeta_zeros():
r"""
List of the imaginary parts of the first 100,000 nontrivial zeros
of the Riemann zeta function. Andrew Odlyzko computed these to
precision within `3\cdot 10^{-9}`.
In order to use ``zeta_zeros()``, you will need to
install the optional Odlyzko database package: ``sage -i
database_odlyzko_zeta``. You can see a list of all
available optional packages with ``sage -optional``.
REFERENCES:
- http://www.dtc.umn.edu/~odlyzko/zeta_tables/
EXAMPLES:
The following example prints the imaginary part of the 13th
nontrivial zero of the Riemann zeta function. Note that only the
first 9 digits after the decimal come from the database. Subsequent
digits are the result of the inherent imprecision of a binary
representation of decimal numbers.
::
sage: zz = zeta_zeros() # optional
sage: zz[12] # optional
59.347044003000001
"""
path = "%s/odlyzko" % PATH
file = "%s/zeros1" % path
if os.path.exists(file + ".pickle"):
misc.verbose("Loading Odlyzko database from " + file + ".pickle")
return db.load(file + ".pickle")
misc.verbose("Creating Odlyzko Database.")
F = [eval(x) for x in open(file).read().split()]
db.save(F, file + ".pickle")
return F
