Re: gp: agm(,) error

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

On Mon, 10 Feb 2003, Michael Somos wrote:
> ? \v
>           GP/PARI CALCULATOR Version 2.2.5 (development CHANGES-1.554)
>           i686 running linux (ix86 kernel) 32-bit version -- debugging
>               (readline v4.2 enabled, extended help not available)
> ? print(polcoeff(agm(1,sqrt(1-16*x+O(x^65))),64)%8)
> 4
>
> which is correct, but
>
> ? \v
>           GP/PARI CALCULATOR Version 2.2.5 (development CHANGES-1.657)
>            UltraSparc (MicroSparc kernel) 32-bit version -- debugging
>               (readline v2.2 enabled, extended help not available)
> ? print(polcoeff(agm(1,sqrt(1-16*x+O(x^65))),64)%8)
> 0
>
> is not.

My pari-dev-2223 patch [to avoid an infinite loop when inexact coefficients were
involved] unwittingly assumed that the coefficients _would_ become inexact.

Fixed.

    Karim.
-- 
Karim Belabas                    Tel: (+33) (0)1 69 15 57 48
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Université Paris-Sud             Email: Karim.Belabas@math.u-psud.fr
F-91405 Orsay (France)           http://www.math.u-psud.fr/~belabas/
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