Karim BELABAS on Wed, 25 Jun 2003 19:34:11 +0200 (MEST)


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Re: pari-2.2.6.alpha released


On Sun, 22 Jun 2003, Alexander Shumakovitch wrote:
> In the meantime, I've stumbled upon another misbehavior:
>   (22:32) gp > Mat(5) * [0]~
>   time = 0 ms.
>   %1 = [0]~
>   (22:33) gp > [Mat(5)] * [[0]~]~
>   time = 0 ms.
>   %3 = 0
>
> The second result is not a column, but a number. It's not the case if
> [0] is replaced with [2], say. No problems with versions <= 2.2.5.

Introduced when speeding up multiplication by sparse vectors [2.2.6-C.25]:
ignoring a component following a positive 'isexactzero' check is incorrect
when the component is not a scalar.

Fixed in CVS.

    Karim.
-- 
Karim Belabas                     Tel: (+33) (0)1 69 15 57 48
Dép. de Mathématiques, Bât. 425   Fax: (+33) (0)1 69 15 60 19
Université Paris-Sud              http://www.math.u-psud.fr/~belabas/
F-91405 Orsay (France)            http://www.parigp-home.de/  [PARI/GP]