[Cado-nfs-discuss] Warnings in log file

Alexander Kruppa alexander.kruppa at inria.fr
Mon Aug 11 23:30:18 CEST 2014


Hi Paul,

no problem, we encountered that issue ourselves once or twice.

We don't store the common root in the polynomial file any more, and consequently cadofactor does no longer parse the m: line. Mixing a new cadofactor with an old polyselect2l (which still prints m:) gives the error you reported.

Nothing in NFS cares for the common root except polynomial selection and the sqrt step, and in the latter it can be recomputed via a simple polynomial GCD. Interestingly, more or less the same thing is true for N, the number to factor, which can be recomputed as the polynomials' resultant. However, we want to keep N as specified by the user around because the resultant may be a multiple of N, especially for SNFS.

Alex


----- Original Message -----
> From: "Paul Leyland" <paul.leyland at gmail.com>
> To: cado-nfs-discuss at lists.gforge.inria.fr
> Sent: Sunday, 10 August, 2014 5:39:09 PM
> Subject: Re: [Cado-nfs-discuss] Warnings in log file
> 
> On Sun, 2014-08-10 at 15:46 +0100, Paul Leyland wrote:
> > On Sun, 2014-08-10 at 15:31 +0100, Paul Leyland wrote:
> > > I'm getting lines such as these in the log file:
> > > 
> > > PID24061 2014-08-10 15:17:25,680 Warning:Polynomial Selection (size
> > > optimized): Invalid polyselect file
> > > '/home/pcl/nums/cado_fact/work/w5_340.upload/w5_340.polyselect1.nu90yb.300000-350000':
> > > Invalid key 'm' in line 'm:
> > > 539674964626763977967326357598007943067461897751243105983674608872801964377960841257117954800435165509502108662569827240434509583101643506969673222196'
> > > 
> > > Should I be concerned?  Does it mean that polynomial finding is going
> > > wrong?
> > > 
> > > A larger nip from the log file is given below so that more context can
> > > be seen.
> > ...
> > 
> > Please hold off dealing with this one for the time being.  I think I
> > found an issue related to a problem I had with an earlier version of
> > CADO-NFS.  For a reason I don't now remember polyselect2 and las had to
> > be in my $PATH which does *not* include a directory deep in the build
> > tree.  I'd forgotten to copy the newly built binaries over to ~/bin and
> > so the initial run was using an elderly version of polyselect2
> > 
> > I'll mail again if the issue occurs now that I've updated
> > ~/bin/polyselect2
> 
> Ok, that was the problem.  My apologies for the false alarm.
> 
> 
> Paul
> 
> 
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