#11673: is_unit not properly implemented for algebraic integers
-----------------------------+----------------------------------------------
Reporter: bober | Owner: davidloeffler
Type: defect | Status: needs_review
Priority: major | Milestone: sage-4.8
Component: number fields | Keywords:
Work_issues: | Upstream: N/A
Reviewer: | Author: Johan Bosman
Merged: | Dependencies: #12185
-----------------------------+----------------------------------------------
Changes (by johanbosman):
* status: needs_work => needs_review
Old description:
> Here is an example:
> {{{
> sage: K.<a> = NumberField(x^2 - x - 1)
> sage: OK = K.ring_of_integers()
> sage: OK(13).is_unit() # should be false!
> True
> sage: OK(1/13)
> ---------------------------------------------------------------------------
> TypeError Traceback (most recent call
> last)
>
> /home/bober/<ipython console> in <module>()
>
> /home/bober/sage/local/lib/python2.6/site-
> packages/sage/structure/parent.so in
> sage.structure.parent.Parent.__call__ (sage/structure/parent.c:7102)()
>
> /home/bober/sage/local/lib/python2.6/site-
> packages/sage/structure/coerce_maps.so in
> sage.structure.coerce_maps.DefaultConvertMap_unique._call_
> (sage/structure/coerce_maps.c:3254)()
>
> /home/bober/sage/local/lib/python2.6/site-
> packages/sage/structure/coerce_maps.so in
> sage.structure.coerce_maps.DefaultConvertMap_unique._call_
> (sage/structure/coerce_maps.c:3157)()
>
> /home/bober/sage/local/lib/python2.6/site-
> packages/sage/rings/number_field/order.pyc in _element_constructor_(self,
> x)
> 1049 V, _, embedding = self._K.vector_space()
> 1050 if not embedding(x) in self._module_rep:
> -> 1051 raise TypeError, "Not an element of the order."
> 1052 return self._element_type(self, x)
> 1053
>
> TypeError: Not an element of the order.
> }}}
>
> This does not seem to be limited to quadratic fields.
New description:
Here is an example:
{{{
sage: K.<a> = NumberField(x^2 - x - 1)
sage: OK = K.ring_of_integers()
sage: OK(13).is_unit() # should be false!
True
sage: OK(1/13)
---------------------------------------------------------------------------
TypeError Traceback (most recent call
last)
/home/bober/<ipython console> in <module>()
/home/bober/sage/local/lib/python2.6/site-
packages/sage/structure/parent.so in sage.structure.parent.Parent.__call__
(sage/structure/parent.c:7102)()
/home/bober/sage/local/lib/python2.6/site-
packages/sage/structure/coerce_maps.so in
sage.structure.coerce_maps.DefaultConvertMap_unique._call_
(sage/structure/coerce_maps.c:3254)()
/home/bober/sage/local/lib/python2.6/site-
packages/sage/structure/coerce_maps.so in
sage.structure.coerce_maps.DefaultConvertMap_unique._call_
(sage/structure/coerce_maps.c:3157)()
/home/bober/sage/local/lib/python2.6/site-
packages/sage/rings/number_field/order.pyc in _element_constructor_(self,
x)
1049 V, _, embedding = self._K.vector_space()
1050 if not embedding(x) in self._module_rep:
-> 1051 raise TypeError, "Not an element of the order."
1052 return self._element_type(self, x)
1053
TypeError: Not an element of the order.
}}}
This does not seem to be limited to quadratic fields.
Apply [attachment:11673.2.patch].
--
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11673#comment:5>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
