#9400: modify the NumberField constructor to pass in optional integer B such
that
all the internal pari routines will replace the discriminant by its gcd
with B, making some things massively faster.
-----------------------------+----------------------------------------------
Reporter: was | Owner: davidloeffler
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-4.5.3
Component: number fields | Keywords:
Author: | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
-----------------------------+----------------------------------------------
Comment(by was):
Hi,
I retract my comment. The issue may be that sorting of elements of number
fields is now useless. Observe:
{{{
sage: L.<b> = NumberField(x^3-10001)
sage: b+1 < L(1667)
False
sage: L(1667) < b + 1
False
}}}
Thus it doesn't matter *what* you do with sorting and uniquing the gens
before or after -- there's no sensible ordering that will come out of
this, unless elements of number fields get a total (non-algebraic)
ordering. I thought they had one.
Oh, now I remember -- there is a *major bug* in the way elements of number
fields are ordered. You can see this by looking at the code (I think Joel
Mohler) wrote in number_field_element.pyx. I fixed this a few weeks ago
as part of the patch bomb #9541.
So my advice is to not worry about sorting issues as part of *this* patch,
but keep in mind that it is has to be fixed later. I've opened ticket
#9752 to fix this.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/9400#comment:13>
Sage <http://www.sagemath.org>
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