Ticket #9476: trac_9476-remove-not-implemented-error.patch

File trac_9476-remove-not-implemented-error.patch, 2.1 KB (added by rlm, 11 years ago)
  • sage/schemes/elliptic_curves/ell_modular_symbols.py

    # HG changeset patch
    # User Robert L. Miller <rlm@rlmiller.org>
    # Date 1279377024 -7200
    # Node ID f2e38847ceb52473191ec1369c87f41e0eed95e1
    # Parent  7fe2142efcadef642952c14af37b5ed3136c9dc1
    #9476: Remove a NotImplementedError
    
    diff -r 7fe2142efcad -r f2e38847ceb5 sage/schemes/elliptic_curves/ell_modular_symbols.py
    a b  
    430430            sage: M=sage.schemes.elliptic_curves.ell_modular_symbols.ModularSymbolECLIB(E,+1)
    431431            sage: M(0)
    432432            1
    433             sage: M=sage.schemes.elliptic_curves.ell_modular_symbols.ModularSymbolECLIB(E,-1)
    434             Traceback (most recent call last):
    435             ...         
    436             NotImplementedError: Negative spaces of Modular Symbols using eclib has not yet been implemented.
    437433
    438434        This is a rank 1 case with vanishing positive twists.
    439435        The modular symbol can not be adjusted::
     
    459455            sage: [C.modular_symbol(use_eclib=True,normalize='none')(0) for C in E.isogeny_class()[0]]
    460456            [1/8, 1/8, 1/8, 1/8, 1/8, 1/8, 1/8, 1/8]
    461457           
     458        Note that ``eclib`` now supports negative spaces of modular symbols,
     459        but there is still an issue with normalization::
     460
     461            sage: M=sage.schemes.elliptic_curves.ell_modular_symbols.ModularSymbolECLIB(E,-1)
     462            Warning : Could not normalize the modular symbols, maybe all further results will be multiplied by -1, 2 or -2.
     463            sage: M(1/5)
     464            3/8
     465
    462466        """
    463467        self._sign = ZZ(sign)
    464468        if self._sign != sign:
    465469            raise TypeError, 'sign must be an integer'
    466470        if self._sign != -1 and self._sign != 1:
    467471            raise TypeError, 'sign must -1 or 1'
    468         if self._sign == -1:
    469             raise NotImplementedError, 'Negative spaces of Modular Symbols using eclib has not yet been implemented.'
    470472        self._E = E
    471473        self._use_eclib = True
    472474        self._base_ring = QQ