Opened 15 years ago

Closed 14 years ago

#1127 closed defect (fixed)

[with patch, positive review] modularSymbol complement fails for E=128a

Reported by: syazdani Owned by: craigcitro
Priority: major Milestone: sage-3.3
Component: modular forms Keywords:
Cc: robertwb Merged in:
Authors: Reviewers:
Report Upstream: Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description

The following code raises the following exception:

sage: E=EllipticCurve("128a")
sage: ME=E.modular_symbol_space()
sage: ME.complement()
---------------------------------------------------------------------------
<type 'exceptions.RuntimeError'>          Traceback (most recent call last)

/net/mathserv/1/home/syazdani/research/programs/<ipython console> in <module>()

/home/syazdani/sage/local/lib/python2.5/site-packages/sage/modular/hecke/submodule.py in complement(self, bound)
    200         else:
    201             # failed
--> 202             raise RuntimeError, "Computation of complementary space failed (cut down to rank %s, but should have cut down to rank %s)."%(V.rank(), self.rank())
    203
    204

<type 'exceptions.RuntimeError'>: Computation of complementary space failed (cut down to rank 18, but should have cut down to rank 1).

Attachments (1)

trac_1127.patch (2.7 KB) - added by AlexGhitza 14 years ago.

Download all attachments as: .zip

Change History (13)

comment:1 Changed 15 years ago by mabshoff

  • Milestone set to sage-2.9

comment:2 Changed 15 years ago by mabshoff

  • Milestone changed from sage-2.10 to sage-2.9.1

comment:3 Changed 15 years ago by mabshoff

This remains unfixed in Sage 2.9.

Cheers,

Michael

comment:4 Changed 15 years ago by mabshoff

And it is still open in Sage 2.10.

Cheers,

Michael

comment:5 Changed 14 years ago by mabshoff

  • Owner changed from was to craigcitro

And it is still broken in Sage 3.0.3. This looks like a job for Craig Citro :)

Cheers,

Michael

comment:6 Changed 14 years ago by mabshoff

Could #2535 be related?

Cheers,

Michael

comment:7 Changed 14 years ago by robertwb

  • Cc robertwb added

comment:8 Changed 14 years ago by AlexGhitza

  • Summary changed from modularSymbol complement fails for E=128a to [with patch, needs review] modularSymbol complement fails for E=128a

For the record, there are other failures for conductors 144, 192, 225. These are the only conductors smaller than 250 that fail.

The patch implements a naive fix.

comment:9 Changed 14 years ago by craigcitro

I'd review this, but I helped write it. :)

comment:10 Changed 14 years ago by robertwb

I'm still getting

sage: E = EllipticCurve("128a") 
sage: E.congruence_number()
------------------------------------------------------------
Traceback (most recent call last):
  File "<ipython console>", line 1, in <module>
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/schemes/elliptic_curves/ell_rational_field.py", line 2618, in congruence_number
    self.__congruence_number = W.congruence_number(V)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 938, in congruence_number
    W = other.q_expansion_module(prec, ZZ)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 770, in q_expansion_module
    return self._q_expansion_module_integral(prec)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 910, in _q_expansion_module_integral
    V = self.q_expansion_module(prec, QQ)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 772, in q_expansion_module
    return self._q_expansion_module_rational(prec)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 861, in _q_expansion_module_rational
    return self._q_expansion_module(prec)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 820, in _q_expansion_module
    return A.span([f.padded_list(prec) for f in self.q_expansion_basis(prec, algorithm)])
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 602, in q_expansion_basis
    return Sequence(self._q_expansion_basis_hecke_dual(prec), cr=True)
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/modsym/space.py", line 1073, in _q_expansion_basis_hecke_dual
    v = [self.dual_hecke_matrix(n).column(i) for n in range(1,prec)]
  File "/Users/robert/sage/sage-3.1.3/local/lib/python2.5/site-packages/sage/modular/hecke/module.py", line 797, in dual_hecke_matrix
    T = self._compute_dual_hecke_matrix(n)
  File "/Users/robert/sage/current/local/lib/python2.5/site-packages/sage/modular/hecke/submodule.py", line 110, in _compute_dual_hecke_matrix
    return A.restrict(self.dual_free_module(), check=check)
  File "/Users/robert/sage/current/local/lib/python2.5/site-packages/sage/modular/hecke/submodule.py", line 320, in dual_free_module
    "(cut down to rank %s, but should have cut down to rank %s)."%(V.rank(), self.rank())
RuntimeError: Computation of embedded dual vector space failed (cut down to rank 9, but should have cut down to rank 8).

comment:11 Changed 14 years ago by robertwb

  • Summary changed from [with patch, needs review] modularSymbol complement fails for E=128a to [with patch, positive review] modularSymbol complement fails for E=128a

This is a separate issue, see #5080. The patch fixes the issue that was raised.

Changed 14 years ago by AlexGhitza

comment:12 Changed 14 years ago by mabshoff

  • Milestone changed from sage-3.4.1 to sage-3.3
  • Resolution set to fixed
  • Status changed from new to closed

Merged in Sage 3.3.alpha2

Cheers,

Michael

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