Error in Quadratic Characters

orever · 2022-11-29, 16:16

Hello, I was running only cado-nfs. To factor a C145 http://factordb.com/index.php?id=1100000000001002967

I'm using the latest version of cado on gitlab

After some days. Error in Quadratic Characters the final log

Error:Quadratic Characters: Stderr output (last 10 lines only) follow (stored in file /tmp/cado.k10p4npc/c145.characters.stderr.5):
Error:Quadratic Characters: done reading heavy block of size 3539102 x 32 at wct=35.2s
Error:Quadratic Characters: /tmp/cado.k10p4npc/c145.bwc/W: 64 vectors
Error:Quadratic Characters: Total: 64 kernel vectors
Error:Quadratic Characters: done reading 64 kernel vectors at wct=35.3s
Error:Quadratic Characters: Info: input kernel vectors reduced to dimension 64
Error:Quadratic Characters: done multiplying matrices at wct=35.7s
Error:Quadratic Characters: Computing left nullspace of 64 x 96 matrix
Error:Quadratic Characters: dim of ker = 0
Error:Quadratic Characters: Error, all dependencies are zero !
Error:Quadratic Characters:

I tried to run it again and got the same error. Can someone help me not to waste all this time. How to continue from here?

swellman · 2022-11-30, 13:32

I cannot tell what went wrong with CADO from the information you provided, but is it safe to assume you have GMP and other tools installed?

Here is a nice and thorough walkthrough of setting up CADO.

If you are trying to learn CADO, fine. But if your primary goal is to factor that particular number, don’t use GNFS but rather SNFS via Yafu. It’s a GNFS 145 difficulty job but only a SNFS 157 difficulty job. 145/157 is 0.9235 but best practice is to only use GNFS when GNFS < 0.69*SNFS, otherwise use SNFS.

Still CADO should have worked for this problem. Let us know.

orever · 2022-11-30, 15:30

It's working fine, I've already factored a c115 with the same configuration and several c90.

This is the first time CADO has had a problem.

I wanted to know if it can be fixed or do I have to start over?

swellman · 2022-11-30, 15:49

Quote:

Originally Posted by orever

It's working fine, I've already factored a c115 with the same configuration and several c90.

This is the first time CADO has had a problem.

I wanted to know if it can be fixed or do I have to start over?

I’ve not seen nor heard of this issue so I can’t help. My only suggestion is to start over but use the improved parameters found here. It should run faster.

Sorry, that’s all I got.

VBCurtis · 2022-11-30, 17:08

I also haven't seen this error, and I have no ideas.

I can tell you CADO has no randomness in its procedure- so if you've seen this outcome twice, restarting with the same params is extremely unlikely to yield a different outcome. If you run it with my params (the ones Sean linked above), chances are decent the bug won't appear again and you'll get factors.

But:
I'm with Sean- use the right tool for the job, and factor this number via SNFS. The best learning for your situation is "how do I create the SNFS polynomial for this job?" Rather than "what is this weird bug?"

You can surely post your bug to the cado mailing list, since you've recreated it a second time.

The bugs I've seen have usually been triggered only when other processes are running on a system while CADO is in the matrix steps. Those have resolved by resuming the job with an idle machine, or with a different number of threads assigned to linear algebra. I haven't seen the outcome you posted, so I don't mean to suggest you have such a situation; merely explaining what I did the few times I suffered crashes on CADO.

orever · 2022-12-05, 22:01

complete factorization.
With improved parameters found https://www.mersenneforum.org/showthread.php?t=28023

2022-11-29, 16:16	#1
orever Oct 2019 1000₂ Posts	Error in Quadratic Characters Hello, I was running only cado-nfs. To factor a C145 http://factordb.com/index.php?id=1100000000001002967 I'm using the latest version of cado on gitlab After some days. Error in Quadratic Characters the final log Error:Quadratic Characters: Stderr output (last 10 lines only) follow (stored in file /tmp/cado.k10p4npc/c145.characters.stderr.5): Error:Quadratic Characters: done reading heavy block of size 3539102 x 32 at wct=35.2s Error:Quadratic Characters: /tmp/cado.k10p4npc/c145.bwc/W: 64 vectors Error:Quadratic Characters: Total: 64 kernel vectors Error:Quadratic Characters: done reading 64 kernel vectors at wct=35.3s Error:Quadratic Characters: Info: input kernel vectors reduced to dimension 64 Error:Quadratic Characters: done multiplying matrices at wct=35.7s Error:Quadratic Characters: Computing left nullspace of 64 x 96 matrix Error:Quadratic Characters: dim of ker = 0 Error:Quadratic Characters: Error, all dependencies are zero ! Error:Quadratic Characters: I tried to run it again and got the same error. Can someone help me not to waste all this time. How to continue from here?

2022-12-05, 22:01	#6
orever Oct 2019 8₁₀ Posts	complete factorization. With improved parameters found https://www.mersenneforum.org/showthread.php?t=28023 Last fiddled with by orever on 2022-12-05 at 22:02

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2022-11-30, 13:32	#2
swellman Jun 2012 111101001010₂ Posts	I cannot tell what went wrong with CADO from the information you provided, but is it safe to assume you have GMP and other tools installed? Here is a nice and thorough walkthrough of setting up CADO. If you are trying to learn CADO, fine. But if your primary goal is to factor that particular number, don’t use GNFS but rather SNFS via Yafu. It’s a GNFS 145 difficulty job but only a SNFS 157 difficulty job. 145/157 is 0.9235 but best practice is to only use GNFS when GNFS < 0.69*SNFS, otherwise use SNFS. Still CADO should have worked for this problem. Let us know.

2022-11-30, 15:30	#3
orever Oct 2019 2³ Posts	It's working fine, I've already factored a c115 with the same configuration and several c90. This is the first time CADO has had a problem. I wanted to know if it can be fixed or do I have to start over?

2022-11-30, 17:08	#5
VBCurtis "Curtis" Feb 2005 Riverside, CA 13140₈ Posts	I also haven't seen this error, and I have no ideas. I can tell you CADO has no randomness in its procedure- so if you've seen this outcome twice, restarting with the same params is extremely unlikely to yield a different outcome. If you run it with my params (the ones Sean linked above), chances are decent the bug won't appear again and you'll get factors. But: I'm with Sean- use the right tool for the job, and factor this number via SNFS. The best learning for your situation is "how do I create the SNFS polynomial for this job?" Rather than "what is this weird bug?" You can surely post your bug to the cado mailing list, since you've recreated it a second time. The bugs I've seen have usually been triggered only when other processes are running on a system while CADO is in the matrix steps. Those have resolved by resuming the job with an idle machine, or with a different number of threads assigned to linear algebra. I haven't seen the outcome you posted, so I don't mean to suggest you have such a situation; merely explaining what I did the few times I suffered crashes on CADO.