Re: bnrL1: wrong values

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

* Igor Schein [2005-03-30 21:09]:
> On Wed, Mar 30, 2005 at 06:51:26PM +0200, Xavier-Francois Roblot wrote:
>> On Tue, 2005-03-29 at 18:31 -0500, buromano@rcn.com wrote:
>> > I'm getting the wrong values from bnrL1 in gp 2.2.9.  An example:
>> >                        GP/PARI CALCULATOR Version 2.2.9 (alpha)
>> >                    PowerPC running darwin (PPC kernel) 32-bit version
>> >        compiled: Mar 29 2005, gcc-3.3 20030304 (Apple Computer, Inc. build
>> > 1495)
>> >                     (readline v4.3 enabled, extended help available)
>> >
>> > ? bnf = bnfinit(x^2 - 229);
>> > ? bnr = bnrinit(bnf,1,1);
>> > ? bnrL1(bnr)
>> > %78 = [[2, 1.747618204302940723551535783 + 2.271919407 E-28*I], [2,
>> > 1.747618204302940723551535783 - 2.271919407 E-28*I], [1,
>> > -4.068697957776515962021319266]]
>> >
>> > should be:
>> >                        GP/PARI CALCULATOR Version 2.2.7 (alpha)
>> >                   Power PC running darwin (PPC kernel) 32-bit version
>> >        compiled: Mar 29 2005, gcc-3.3 20030304 (Apple Computer, Inc. build
>> > 1495)
>> >                   (readline not compiled in, extended help available)
>> > ? bnf = bnfinit(x^2 - 229);
>> > ? bnr = bnrinit(bnf,1,1);
>> > ? bnrL1(bnr)
>> > [[2, 2.355454590844564506512740955 + 2.776790386 E-28*I], [2,
>> > 2.355454590844564506512740955 - 2.776790386 E-28*I], [1,
>> > -4.068697957776515962021319266]]
>> > Am I missing something?
>>
>> Hi, thanks for the bug report. I fixed the bug in the CVS version. It
>> turns out the program was using a routine to compute values of
>> L-functions specific for quadratic fields but only for the kind of
>> extensions used to construct abelian extensions using Stark units (as in
>> the functions quadhilbert or bnrstark).
>>
>> Xavier
>
> Well, we have a regression:
>
> ? bnrL1(bnrinit(bnfinit(y^2+6),1,1),0)
>   *** bnrL1: exponent (expo) overflow

It's fixed in CVS.

Thanks!

    Karim.
--
Karim Belabas                     Tel: (+33) (0)1 69 15 57 48
Dep. de Mathematiques, Bat. 425   Fax: (+33) (0)1 69 15 60 19
Universite Paris-Sud              http://www.math.u-psud.fr/~belabas/
F-91405 Orsay (France)            http://pari.math.u-bordeaux.fr/  [PARI/GP]