Discussion related to cado-nfs

[Paul Leyland <paul.leyland@gmail.com>]

On Sat, 2013-04-06 at 14:05 +0200, Zimmermann Paul wrote:

> any news of your first factorization with CADO-NFS?

Yes.  Success, at last.

Info:Calling Block-Wiedemann...
Info:Adding characters...
    Info:25 vectors remaining after characters.
Info:--------------------------------------------------------------------------
Info:Square root
Info:--------------------------------------------------------------------------
Info:Preparing 25 dependency files
Info:Testing dependency number 0...
    Info:Factorization was successful!

Info:938162157466439248706242446740994666550032835844927071820158466530202226253
 [prime]

Info:167833726244347054883741985866275357519984119769032664266435089934119867 
[prime]
    Info:Doing gcds with previously known composite factors
    Info:non-trivial factor:
938162157466439248706242446740994666550032835844927071820158466530202226253 
[prime]
    Info:non-trivial factor:
167833726244347054883741985866275357519984119769032664266435089934119867
[prime]
    Info:Now: 2 prime factors, 0 composite factors
    Info:Factorization complete
Info:--------------------------------------------------------------------------
Info:All done!
Info:--------------------------------------------------------------------------
167833726244347054883741985866275357519984119769032664266435089934119867
938162157466439248706242446740994666550032835844927071820158466530202226253

Nice to see it was not an ECM miss.

This number was the last remaining sub-C150 composite from the
generalized Cullen & Woodall tables at
http://www.leyland.vispa.com/numth/factorization/cullen_woodall/cw.html
and was the cofactor of GC(8,233) aka 233*8^233+1.

With one exception, all the problems I had with the CADO-NFS
factorization arose from my incompetence.  I expected to hit various
issues with a new (to me) and complex piece of software because I've had
similar experiences in the past with the CWI suite and with
msieve/ggnfs.  CADO-NFS was certainly *much* easier to build than ggnfs!

The one exception is that cadofactor.pl doesn't handle relative paths
properly.  Most of the time they work fine but the linear algebra fails.
Someone with ability to create a bug report in the tracker should do so.
I don't have the requisite permissions.

Thanks all.

Paul L.