On Wednesday, December 23, 2015 at 10:57:26 PM UTC+1, vdelecroix wrote:
>
> Your expression
>
> my_expr = (a10 + u10/u00 - u01*u10^2/(u00^2*(u01*u10/u00 - u11)) +
> u10*u11/(u00*(u01*u10/u00 - u11)))
>
> is not really a fraction. So I do not understand what you mean by
> "correct behavior".
> You can recover the previous behavior using
> sage: my_expr.simplify_rational()
> a10
>
Vincent, you're just working around a bug that has nothing to do
with a numerator but with normalization in Pynac:
sage: a,b,c,d,e=var('a,b,c,d,e')
sage: (e + c/a - b*c^2/(a^2*(b*c/a-d)) + c*d/(a*(b*c/a-d))).normalize()
(a^2*b*c*e - a^3*d*e)/((b*c - a*d)*a^2)
which is incorrect by any definition (should be e).
Calling simplify_rational() bypasses Pynac and calls Maxima.
I opened a ticket:
http://trac.sagemath.org/ticket/19775
Thanks for the bug report!
--
You received this message because you are subscribed to the Google Groups
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sage-devel+unsubscr...@googlegroups.com.
To post to this group, send email to sage-devel@googlegroups.com.
Visit this group at https://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/d/optout.
