lanczos error: submatrix is not invertible
 

I'm trying to postprocess [URL="http://escatter11.fullerton.edu/nfs/crunching.php"]GC_6_302[/URL] using Brian Gladman's [URL="http://gilchrist.ca/jeff/factoring/index.html"]1.52dev SVN 942[/URL] Windows build. I get this error when the Lanczos begins:
[CODE]Wed Feb 12 12:07:54 2014 commencing Lanczos iteration (4 threads)
Wed Feb 12 12:07:54 2014 memory use: 3067.7 MB
Wed Feb 12 12:08:22 2014 lanczos error: submatrix is not invertible
Wed Feb 12 12:08:22 2014 lanczos halted after 4 iterations (dim = 191)
Wed Feb 12 12:08:22 2014 linear algebra failed; retrying...
Wed Feb 12 12:08:22 2014 commencing Lanczos iteration (4 threads)
Wed Feb 12 12:08:22 2014 memory use: 3067.7 MB
Wed Feb 12 12:08:33 2014 lanczos error: submatrix is not invertible
Wed Feb 12 12:08:33 2014 lanczos halted after 1 iterations (dim = 0)
Wed Feb 12 12:08:33 2014 linear algebra failed; retrying...
[/CODE]
I've heard that there is a newer build of msieve, about SVN 956, but I don't know of any 64-bit Windows builds of it available. I didn't specify a target_density for this attempt.
Does this build have problems post-processing, or is there something else wrong?

Yes, I think 942 is a version which has the memory-corruption bug, whose symptoms include that message.

You can try this one if you like. I use it without issue. You may need a pthread dll, but you should be able to find that no problem.

Edit: Note that this one does NOT have CUDA enabled. I use it just for the linear algebra.

I have been using the windows 1.52 'official' release from souceforge since Jason announced it (see announcements thread). Is that 32-bit only? That release includes the dlls too.

[QUOTE=wombatman;366797]You can try this one if you like. I use it without issue. You may need a pthread dll, but you should be able to find that no problem.

Edit: Note that this one does NOT have CUDA enabled. I use it just for the linear algebra.[/QUOTE]

Got it working using this, thanks! :smile:

[QUOTE=VBCurtis;366804]I have been using the windows 1.52 'official' release from souceforge since Jason announced it (see announcements thread). Is that 32-bit only? That release includes the dlls too.[/QUOTE]

I think so.

Mini-Geek, happy to help!

The sourceforge release is only for 32-bit windows. Any other binaries will have to come from elsewhere.