Re: Some bugs?

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Sat, Jul 04, 2009 at 12:24:00PM +0100, Jason Moxham wrote:
> On Thursday 02 July 2009 23:11:31 Jason Moxham wrote:
> I manage to get rid of a few more bugs, and I'm left with these
> 
> polred,rnf,rnfkummer all have this error
> 
> x^7 + Mod(7*y - 7, y^2 - y - 1)*x^6 + Mod(-21*y + 28, y^2 - y - 1)*x^5 - 35*
> x^4 + Mod(35*y - 49, y^2 - y - 1)*x^3 + Mod(-7*y + 84, y^2 - y - 1)*x^2 + Mo
> d(-14*y + 21, y^2 - y - 1)*x + Mod(-y - 43, y^2 - y - 1)
>   ***   at top-level: rnfpolredabs(nfinit(
>   ***                 ^--------------------
>   *** rnfpolredabs: could not open requested file ./MPQS.gpa/FREL.

There might a problem with the way MPQS creates temporary files.
Try factor(2^128+1)
The code to create temporary files is in src/language/es.c.
Maybe we use a wrong directory or a wrong filename.

>   ***   at top-level: fptest(10007,Mod(1,1
>   ***                 ^--------------------
>   ***   in function fptest: ...,if(subst(P,x,C[i])==0,0,error("fptest("a","l
>   ***                                                   ^--------------------
>   ***   user error: fptest(a,10007,Mod(1, 10007)*x^30 + Mod(7812, 10007)*x^28 
> + Mod(7090, 10007)*x^27 + Mod(7645, 10007)*x^26 + Mod(4110, 10007)*x^25 + 
> Mod(3307, 10007)*x^24 + Mod(5763, 10007)*x^23 + Mod(7900, 10007)*x^22 + 
> Mod(3872, 10007)*x^21 + Mod(8123, 10007)*x^20 + Mod(4076, 10007)*x^19 + 
> Mod(3265, 10007)*x^18 + Mod(3777, 10007)*x^17 + Mod(3398, 10007)*x^16 + 
> Mod(5674, 10007)*x^15 + Mod(4018, 10007)*x^14 + Mod(6820, 10007)*x^13 + 
> Mod(6479, 10007)*x^12 + Mod(984, 10007)*x^11 + Mod(5652, 10007)*x^10 + 
> Mod(1129, 10007)*x^9 + Mod(7573, 10007)*x^8 + Mod(1822, 10007)*x^7 + Mod(837, 
> 10007)*x^6 + Mod(4169, 10007)*x^5 + Mod(4787, 10007)*x^4 + Mod(1616, 
> 10007)*x^3 + Mod(5185, 10007)*x^2 + Mod(2649, 10007)*x + Mod(1483, 
> 10007),Mod(1, 10007)*x^30 + Mod(1, 10007)*x + Mod(2, 10007))

factorff returns a wrong result.

Try the following command:
{
factorff(x^30 + 7812*x^28 + 7090*x^27 + 7645*x^26 + 4110*x^25 + 3307*x^24 + 5763*x^23 + 7900*x^22 + 3872*x^21 + 8123*x^20 + 4076*x^19 + 3265*x^18 + 3777*x^17 + 3398*x^16 + 5674*x^15 + 4018*x^14 + 6820*x^13 + 6479*x^12 + 984*x^11 + 5652*x^10 + 1129*x^9 + 7573*x^8 + 1822*x^7 + 837*x^6 + 4169*x^5 + 4787*x^4 + 1616*x^3 + 5185*x^2 + 2649*x + 1483, 10007, a^30 + a + 2)
}

> and nffactor
> 
>   ***   Warning: new stack size = 16000000 (15.259 Mbytes).
>   ***   at top-level: ...17057741307681944498*x^48+1269570586472186440
>   ***                                             ^--------------------
>   ***   bug in PARI/GP (Segmentation Fault), please report

This one might be a consequence of the previous problem. (nffactor 
use factorff internally).

Cheers,
Bill.