#5338: Sage 3.2.2: speed regression/infinite loop for "K.<b> = QQ[a]"
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Reporter: mabshoff | Owner: tbd
Type: defect | Status: needs_work
Priority: critical | Milestone: sage-4.3
Component: algebra | Keywords:
Work_issues: | Author:
Reviewer: | Merged:
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Changes (by robertwb):
* status: needs_review => needs_work
Comment:
{{{
sage: b = sin(pi/5)
sage: time sage.calculus.calculus.minpoly(b, algorithm='algebraic')
CPU times: user 0.05 s, sys: 0.00 s, total: 0.05 s
Wall time: 0.05 s
x^4 - 5/4*x^2 + 5/16
sage: time sage.calculus.calculus.minpoly(b)
Traceback (most recent call last):
...
NotImplementedError: Could not prove minimal polynomial x^4 - 5/4*x^2 +
5/16 (epsilon 0.00000000000000e-1)
}}}
We need to wrap raising this error to not be raised if the algorithm is
numeric...
I remember doing it in this order because there were cases where the
numeric algorithm was way slower, but at least the numeric one finishes in
constant bounded time.
I really feel there should be a quicker way of computing compositums than
using QQbar.
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Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/5338#comment:9>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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