Re: formal ellinit

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

* Bill Allombert [2012-06-11 14:06]:
> Dear PARI developers,
> 
> I found a way to do a formal ellinit which is sometimes useful:
> 
> ? a6;a4;a3;a2;a1;E=ellinit([a1,a2,a3,a4,a6],1);
> ? ##
>   ***   last result computed in 0 ms.
> 
> This is useful because the more straightforward
> a1;a2;a3;a4;a6;ellinit([a1,a2,a3,a4,a6],1);
> does not really work (much much slower).

I committed a workaround for the original problem in master:

(23:51) colibri-kb% gp -f
[...]
? ellinit([a1,a2,a3,a4,a6],1);
? ##
  ***   last result computed in 8 ms.

[ Basically, gcd(c4^3, D) can be computed faster by starting from gcd(c4,D) and
simplifying incrementally... ]

Thanks for noticing this :-)

    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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