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Old 2016-02-06, 04:28   #1
jux
 
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Default Error reading relation

I am currently on the -nc step, and YAFU currently spits out some lines like error -15 reading relation 32507626, with all other millions of relations I presume being read correctly. Is this normal?

I cannot run -nc2 without getting this error: read_cycles can't open cycle file. To my knowledge, I have completed -np, -ns, and -nc.

Last fiddled with by jux on 2016-02-06 at 04:56
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Old 2016-02-06, 05:17   #2
LaurV
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Occasional relations can be bad, this is caused by a race condition when relations are written in the file, numbers of one relation can be missed or interleaved with numbers from other relation. If more than (guessing) 1% of the relations give you reading error, then you may have a problem (like it happened to me in the past I was sieving two different polys) but if only few (few hundreds, few thousand) relations are bad, it is of no concern.

edit: if you are really nitpicking about, and have a text editor that support such large files, then just identify the bad relations, go into the file and erase the lines
Also, forcing a filtering step will eliminate your duplicate relations, and the bad one will go lost together with them.

Last fiddled with by LaurV on 2016-02-06 at 05:24
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Old 2016-02-06, 05:37   #3
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Alright, I'm pretty sure the issue with the cycle file does not have to do with reading relations. Do you know how you usually get a cycle file?
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Old 2016-02-06, 07:30   #4
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It should be automatically created as part of the -nc process (I'm not certain which part). I would say it's probably an issue with file permissions, though that should have make itself apparent long before you got to -nc.
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Old 2016-02-06, 07:48   #5
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It seems like all the steps, including -nc, finished correctly (end of -nc in screenshot), so I'm not sure what the problem is here. I guess I'll give my computer a break tonight.
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Old 2016-02-06, 08:08   #6
LaurV
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Quote:
Originally Posted by jux View Post
It seems like all the steps, including -nc, finished correctly (end of -nc in screenshot), so I'm not sure what the problem is here. I guess I'll give my computer a break tonight.
You have much more ideals than relations. Are you over/under-sieved? You were ok before the last step, it seems. Can you cut out about 5-10% of the relations file and run again, with resume? It may possible try to sieve more, etc. But it is a pity to throw away the work already done.
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Old 2016-02-06, 08:31   #7
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Quote:
Originally Posted by jux View Post
It seems like all the steps, including -nc, finished correctly (end of -nc in screenshot), so I'm not sure what the problem is here. I guess I'll give my computer a break tonight.
-nc did not finish correctly, in fact you didn't even get to -nc2.
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Old 2016-02-07, 08:57   #8
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Quote:
Originally Posted by LaurV View Post
You have much more ideals than relations. Are you over/under-sieved? You were ok before the last step, it seems. Can you cut out about 5-10% of the relations file and run again, with resume? It may possible try to sieve more, etc. But it is a pity to throw away the work already done.
I don't know about over/under-sieved, but -ns seemed to run to completion and the nfs.dat file is 5.8 GB, which is about the size of the .dat file I have from a successful C150 factoring. I don't even know how to cut 5-10% from the relations file of that size - what program do I even use? I guess file.truncate with python (or sed, or some windows batch trick).
I think this may be just an issue with YAFU - my C150 attempt used factmsieve.py and worked fine.

Last fiddled with by jux on 2016-02-07 at 09:11
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Old 2016-02-07, 09:34   #9
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38M unique relations sounds kind of low for a C155. Can you post the contents of your nfs.job file, and try continuing with -ns instead of -nc? I don't think you're done sieving.

If LaurV is right, then there is a truncate command on most Linuxes, or the Python you mentioned would work too.
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Old 2016-02-07, 09:46   #10
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Here is nfs.job, which I remember manually editing . That may have caused problems.
Anyway I figured out how to truncate by lines using wc and sed. So I'll try sieving more.

Code:
n: 10941738641570527421809707322040357612003732945449205990913842131476349984288934784717997257891267332497625752899781833797076537244027146743531593354333897
skew: 71994382.30
Y0: -3137301482625007833545663308178
Y1: 58950047158989383
c0: 61702731036896719906612929448642480018731
c1: -4099166098410202538646695681603748
c2: -32522921176495846591845785
c3: 2916461378816208604
c4: 11304125346
c5: 36

rlim: 32000000
alim: 32000000
lpbr: 29
lpba: 29
mfbr: 58
mfba: 58
rlambda: 2.6
alambda: 2.6
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Old 2016-02-07, 10:37   #11
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The parameters look alright, but 38M unique relations is indeed too low for a C155 (e.g. a 512-bit semi-prime). 5M unique relations is about the bare minimum for building a matrix, and 5M more unique relations doesn't hurt.
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