Re: Field inclusion problem

[Karim Belabas <Karim.Belabas@math.u-bordeaux1.fr>]

* Bill Allombert [2013-01-28 19:11]:
> On Mon, Jan 28, 2013 at 09:50:36AM -0800, Thomas D. Dean wrote:
> > 
> > On 01/24/13 01:20, Karim Belabas wrote:
> > 
> > >
> > >This is more complicated than just nffactor above, a few hours in this
> > >case and you'll probably get no improvement. It might be better to start
> > >from T = polredbest(A) [ will be monic ], and iterate polcompositum(T,T)
> > >and polredbest() to obtain a "simple" (monic) polynomial.
> > 
> > gp > polred(polyB)
> > 
> > gp 2.5.3, Core i7-3930k O.C. 4.2Ghz, 16GB RAM, after 65 hours this is
> > still running.
> > 
> > Any guesstimate on running time?
> 
> Maybe try polred(polyB,1) to skip the factorization and use \g4 to set
> the DEBUG output.
> 
> If you are not using windows, you can interrupt your current computation
> with Control-C, do \g4 and enter return to continue.
> If it looks like running ECM factorisation, kill it and restart with
> polred(polyB,1).

An alternative would be to install a recent development version (2.6.*),
and really use polredbest() directly. As it stands --  after applying
Bill's advice --, polred is going to try fewer polynomials than
polredbest would, with even smaller chances of improvement.

Cheers,

    K.B.
--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite Bordeaux 1          Fax: (+33) (0)5 40 00 69 50
351, cours de la Liberation    http://www.math.u-bordeaux1.fr/~belabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux1.fr/  [PARI/GP]
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