Indeed, 1e-30 is too precise. Changing to 1e-10 makes it work.
The solution at https://github.com/sagemath/sage/pull/35414 is more robust.
Le samedi 1 avril 2023 à 21:21:05 UTC+2, William Stein a écrit :
> Thanks Vincent! What version of Sage are you using? With sage-9.8 I get:
>
> ---
>
> from
Thank you all for your help!
I got the same error as William, but it pointed me into the right
direction. I found a way how to get the unique bounding interval of the
root in sympy and convert this interval to a sage interval. It is not the
prettiest solution but the following works for me:
Indeed. Sorry. One needs to take a larger error
sage_approx = RIF(exp.n()) + RIF(-1e-10, 1e-10)
Not the best way to proceed. The solution at
https://github.com/sagemath/sage/pull/35414 should be be more robust.
Le samedi 1 avril 2023 à 21:21:05 UTC+2, William Stein a écrit :
> Thanks Vincent!
Indeed, one has to increase the error to make it work
sage_approx = RIF(exp.n()) + RIF(-1e-10, 1e-10)
This is not the smartest way to proceed.
Le samedi 1 avril 2023 à 21:21:05 UTC+2, William Stein a écrit :
> Thanks Vincent! What version of Sage are you using? With sage-9.8 I get:
>
> ---
>
>
Thanks Vincent!What version of Sage are you using? With sage-9.8 I get:
---
from sympy import sympify
exp = sympify("CRootOf(x**5 + x + 1, 0)")
sage_poly = QQ['x'](list(map(QQ, reversed(exp.poly.rep.rep
sage_approx = RIF(exp.n()) + RIF(-1e-30, 1e-30)
QQbar.polynomial_root(sage_poly,
Dear Marcel,
It is a pity that this does not work more directly. Here is a work around
to achieve what you want to do
sage: exp = sympify("CRootOf(x**5 + x + 1, 0)")
sage: sage_poly = QQ['x'](list(map(QQ, reversed(exp.poly.rep.rep
sage: sage_approx = RIF(exp.n()) + RIF(-1e-30, 1e-30)
sage:
