Re: Error in qfauto() && Happy New Year

Karim Belabas <[email protected]>
Newsgroups gmane.comp.mathematics.pari.devel
Message-ID <[email protected]>
* Georgi Guninski [2022-01-01 10:56]:
> M1=[1, 0, 0, 0, 0, 1, 0, 1, 0, 1; 0, 1, 1, 0, 1, 0, 0, 0, 1, 0; 0, 1,
> 1, 0, 0, 0, 1, 1, 0, 0; 0, 0, 0, 1, 1, 1, 0, 0, 0, 1; 0, 1, 0, 1, 1,
> 0, 1, 0, 0, 0; 1, 0, 0, 1, 0, 1, 0, 1, 0, 0; 0, 0, 1, 0, 1, 0, 1, 0,
> 1, 0; 1, 0, 1, 0, 0, 1, 0, 1, 0, 0; 0, 1, 0, 0, 0, 0, 1, 0, 1, 1; 1,
> 0, 0, 1, 0, 0, 0, 0, 1, 1]
> qfauto(M1,M1)
> *** impossible inverse in divrr: 0.E-19.

Bad Input Bug: M1 must be a positive definite quadratic form, but

(16:33) gp > qfsign(M1)
%1 = [7, 3]

qfauto(M1) also fails. The error actually occurs in qflllgram(M1)
(BIB: M1 is not a Gram matrix...)

Happy New Year to all !

    K.B.
--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite de Bordeaux         Fax: (+33) (0)5 40 00 21 23
351, cours de la Liberation    http://www.math.u-bordeaux.fr/~kbelabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
`
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.