Yep, this was a bug. Fix is up here: http://trac.sagemath.org/sage_trac/ticket/3272
Give it a try, and let me know if you run into any more trouble. -cc On Thu, May 22, 2008 at 11:13 AM, Kirill Vankov <[EMAIL PROTECTED]> wrote: > > Is there any way to define a polynomial ring over a sparse quotient > ring? > > This works: > sage: p = 5 > sage: A.<T> = PolynomialRing(Integers(p)) > sage: f = T^2+1 > sage: B = A.quo(f) > sage: print B > sage: C.<s> = PolynomialRing(B) > sage: print C > Univariate Quotient Polynomial Ring in Tbar over Ring of integers > modulo 5 with modulus T^2 + 1 > Univariate Polynomial Ring in s over Univariate Quotient Polynomial > Ring in Tbar over Ring of integers modulo 5 with modulus T^2 + 1 > > But this does not work: > sage: p = 5 > sage: A.<T> = PolynomialRing(Integers(p),sparse=True) > sage: f = T^2+1 > sage: B = A.quo(f) > sage: print B > sage: C.<s> = PolynomialRing(B) > Univariate Quotient Polynomial Ring in Tbar over Ring of integers > modulo 5 with modulus T^2 + 1 > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "/home/kvankov/.sage/sage_notebook/worksheets/admin/16/code/ > 189.py", line 11, in <module> > exec compile(ur'C = PolynomialRing(B,names=(\u0027s\u0027,)); (s,) > = C._first_ngens(Integer(1))' + '\n', '', 'single') > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sympy/plotting/", line 1, in <module> > > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/polynomial/ > polynomial_ring_constructor.py", line 256, in PolynomialRing > R = _single_variate(base_ring, name, sparse) > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/polynomial/ > polynomial_ring_constructor.py", line 329, in _single_variate > elif base_ring.is_field(): > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/polynomial/ > polynomial_quotient_ring.py", line 412, in is_field > return self.base_ring().is_field() and > self.modulus().is_irreducible() > File "polynomial_element.pyx", line 3762, in > sage.rings.polynomial.polynomial_element.Polynomial.is_irreducible > File "polynomial_element.pyx", line 2109, in > sage.rings.polynomial.polynomial_element.Polynomial.factor > File "polynomial_element.pyx", line 2118, in > sage.rings.polynomial.polynomial_element.Polynomial._factor_pari_helper > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/polynomial/polynomial_ring.py", > line 243, in __call__ > return C(self, x, check, is_gen, construct=construct) > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/polynomial/ > polynomial_element_generic.py", line 95, in __init__ > self.__coeffs[i] = R(z) > File "/usr/local/sage-2.11-ubuntu32-intel-i686-Linux/local/lib/ > python2.5/site-packages/sage/rings/integer_mod_ring.py", line 579, in > __call__ > return integer_mod.IntegerMod(self, x) > File "integer_mod.pyx", line 129, in > sage.rings.integer_mod.IntegerMod > File "integer_mod.pyx", line 1380, in > sage.rings.integer_mod.IntegerMod_int.__init__ > File "integer_ring.pyx", line 274, in > sage.rings.integer_ring.IntegerRing_class.__call__ > File "integer.pyx", line 377, in sage.rings.integer.Integer.__init__ > File "gen.pyx", line 750, in sage.libs.pari.gen.gen.__hex__ > TypeError: gen must be of PARI type t_INT > > K. > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
