[Cado-nfs-discuss] "characters" fails with "all dependencies are zero"

Raphaël Rigo ml-cado at syscall.eu
Mon Aug 4 13:40:54 CEST 2014


Hello,
I'm trying to factor a c154 with cado-nfs.

While I initialy used cadofactor.py, at some point I switched to
manually running tools.
bwc.pl :complete went OK.

But when I try to run "characters" I get this error :

characters.rd539d44 -t 1 -poly best.p -purged rsa512.purge.purged.gz
-index rsa512.merge.index.gz -heavyblock rsa512.merge.small.dense.bin
-nchar 50 -out out.ker -ker rsa512.merge.small.bin-2x2/W -lpbr 30 -lpba 30
Note: total 64 characters, including 14 trivial padding characters
Reading 18943597 (a,b) pairs from rsa512.purge.purged.gz
Read 1024 relations in 0.0s -- 9.1 MB/s -- 80992.8 rels/s
Read 2048 relations in 0.0s -- 17.3 MB/s -- 154043.6 rels/s
Read 4096 relations in 0.0s -- 31.6 MB/s -- 281259.1 rels/s
Read 8192 relations in 0.0s -- 34.7 MB/s -- 308571.4 rels/s
Read 16384 relations in 0.0s -- 47.1 MB/s -- 418781.2 rels/s
Read 32768 relations in 0.1s -- 58.8 MB/s -- 523074.8 rels/s
Read 65536 relations in 0.1s -- 69.7 MB/s -- 620118.1 rels/s
Read 131072 relations in 0.2s -- 79.5 MB/s -- 707560.1 rels/s
Read 262144 relations in 0.3s -- 84.8 MB/s -- 754123.7 rels/s
Read 524288 relations in 0.7s -- 89.1 MB/s -- 791917.1 rels/s
Read 1048576 relations in 1.3s -- 92.4 MB/s -- 821132.8 rels/s
Read 2097152 relations in 2.5s -- 95.1 MB/s -- 844060.8 rels/s
Read 4194304 relations in 4.9s -- 96.7 MB/s -- 862620.6 rels/s
Read 8388608 relations in 9.8s -- 95.5 MB/s -- 854676.3 rels/s
Read 16777216 relations in 19.7s -- 95.3 MB/s -- 853704.3 rels/s
Done: Read 18943597 relations in 22.0s -- 95.9 MB/s -- 860726.7 rels/s
Computing 64 characters for 18943597 (a,b) pairs
all_A freed
all_B freed
done building big character matrix at 337.9
done building small character matrix at 346.8
done reading heavy block of size 5890275 x 32 at 348.8
rsa512.merge.small.bin-2x2/W: 64 vectors
Total: 64 kernel vectors
done reading 64 kernel vectors at 348.9
Info: input kernel vectors reduced to dimension 0
done multiplying matrices at 348.9
Computing left nullspace of 0 x 96 matrix
dim of ker = 0
Error, all dependencies are zero !

I must admit I'm at loss here. Did I make an error before or may it be a
bug ?
I tried both latest git and release 2.1. most of the work was done with
a git version from may I think.

Regards,
Raphaël


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