#11368: can't coerce pari to rational function field
-------------------------------------------------+-------------------------
Reporter: katestange | Owner: robertwb
Type: defect | Status: new
Priority: minor | Milestone: sage-6.1
Component: coercion | Resolution:
Keywords: coercion pari rational | Merged in:
fraction_field string | Reviewers:
Authors: | Work issues:
Report Upstream: N/A | Commit:
Branch: | Stopgaps:
Dependencies: |
-------------------------------------------------+-------------------------
Comment (by pbruin):
The problem seems to be this:
{{{
sage: R.<x,y> = PolynomialRing(QQ)
sage: a=pari((x+y)/y); a
1/y*x + 1
sage: a.numerator()
1/y*x + 1
sage: a.denominator()
1
}}}
Note that the following does work:
{{{
sage: b=pari((x+y)/x); b
(x + y)/x
sage: b.numerator()
x + y
sage: b.denominator()
x
}}}
Note also that the PARI types are different:
{{{
sage: a.type()
't_POL'
sage: b.type()
't_RFRAC'
}}}
This difference arises because PARI treats multivariate polynomials as
iterated univariate polynomials. To PARI, ''a'' lives in
'''Q'''(''y'')[''x''], and ''b'' in Frac('''Q'''[''y''][''x'']).
The solution is probably to convert PARI elements of type `t_POL`
coefficientwise into ''S''.
--
Ticket URL: <http://trac.sagemath.org/ticket/11368#comment:4>
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 unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/groups/opt_out.
