mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > YAFU

Reply
 
Thread Tools
Old 2012-09-16, 18:43   #78
jrk
 
jrk's Avatar
 
May 2008

3×5×73 Posts
Default

Quote:
Originally Posted by Dubslow View Post
Code:
lanczos error: only trivial dependencies found
This is the problem.

Try running -nc again with only 15M relations.
jrk is offline   Reply With Quote
Old 2012-09-16, 19:10   #79
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

3×29×83 Posts
Default

Quote:
Originally Posted by jrk View Post
This is the problem.

Try running -nc again with only 15M relations.
Oh, I didn't even see that.

How would too many relations cause only trivial dependencies? Or is it that the BL algorithm fails somehow?

I'll truncate the rel file and try again.
Dubslow is offline   Reply With Quote
Old 2012-09-16, 20:22   #80
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

11100001101012 Posts
Default

Quote:
Originally Posted by Dubslow View Post
Oh, I didn't even see that.

How would too many relations cause only trivial dependencies? Or is it that the BL algorithm fails somehow?

I'll truncate the rel file and try again.
Thanks again, that did the trick, although the matrix took quite a bit longer to solve. (50 minutes; though it was actually smaller, it was also about +20 weight/col more dense.)
Dubslow is offline   Reply With Quote
Old 2012-09-17, 01:42   #81
jasonp
Tribal Bullet
 
jasonp's Avatar
 
Oct 2004

353710 Posts
Default

Nobody is sure, but even with other packages an NFS matrix will become impossible to solve with enough oversieving.
jasonp is offline   Reply With Quote
Old 2012-09-17, 01:47   #82
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

3×29×83 Posts
Default

Quote:
Originally Posted by jasonp View Post
Nobody is sure, but even with other packages an NFS matrix will become impossible to solve with enough oversieving.

Talk about counter-intuitive.

What about with Gaussian Elimination? Theoretically, as long as there are more columns than rows...
Dubslow is offline   Reply With Quote
Old 2012-09-17, 02:34   #83
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

3×55 Posts
Default

x+y=7
2x+2y=14
3x+3y=21
etc.
Solve?
LaurV is offline   Reply With Quote
Old 2012-09-17, 02:46   #84
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

3×29×83 Posts
Default

Quote:
Originally Posted by LaurV View Post
x+y=7
2x+2y=14
3x+3y=21
etc.
Solve?
There's an infinite number of solutions, though I'm not sure what this has to do with anything, because were not solving for the null space of ((1,1),(2,2),(3,3)) by finding (x,y), and this certainly has more rows than columns...
Dubslow is offline   Reply With Quote
Old 2012-09-17, 03:37   #85
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

249F16 Posts
Default

Grrr, scrap that! I tried to play smart a$$ before the morning coffee...
Right now I understood what you wanted to say...
LaurV is offline   Reply With Quote
Old 2012-09-17, 05:25   #86
Kosmaj
 
Kosmaj's Avatar
 
Nov 2003

1110001001102 Posts
Default

Has anybody tried to factor 1000+ digit numbers with Yafu? (Of course, sieving methods cannot be used, but Yafu is still better than plain ecm to automate the process, and keep track of found factors.)

The other day I started with 3 numbers with about 1600 digits, everything was working great, and I reached t30 without any problems.

Then I switched to numbers with about 1000-1020 digits, a few of them were all right, then problems began. On one number Yafu crashed with an "unrecognized character on input line" kind of error, on the next one with "too many allocs or frees" error. I'm not sure but it seems it happened when Yafu was about to start ecm.
The above was with Yafu-1.32.1 on linux (no external ecm), with the same version on Windows-7 Yafu crashed on the very first of these numbers (which Yafu on linux was able to process).

This is all happening in the batch mode, with "pretest -plan custom" and "-pretest_ratio" 0.02 or 0.03.
BTW, is there a way to tell Yafu to stop ecm on a particular fixed level, say t30, independent of the size of the input number? "-preset_ratio" works but it accepts only 2 fractional digits, if I try 0.025 it is converted to 0.03.
Even with preset_ratio accepting more fractional digits, an option like "preset_level t30" will be better.

Thanks!
Kosmaj is offline   Reply With Quote
Old 2012-09-17, 10:53   #87
jasonp
Tribal Bullet
 
jasonp's Avatar
 
Oct 2004

67218 Posts
Default

Quote:
Originally Posted by Dubslow View Post

Talk about counter-intuitive.

What about with Gaussian Elimination? Theoretically, as long as there are more columns than rows...
It isn't that simple; if there are more columns than rows but some of those columns are linear combinations of each other, then you may not have a nontrivial nullspace. My theory is that this is what happens when you have too much oversieving, matrix columns start to look more and more alike because the relations that contribute to them get mixed together too much.
jasonp is offline   Reply With Quote
Old 2012-09-17, 13:42   #88
bsquared
 
bsquared's Avatar
 
"Ben"
Feb 2007

340410 Posts
Default

Quote:
Originally Posted by Kosmaj View Post
Has anybody tried to factor 1000+ digit numbers with Yafu? (Of course, sieving methods cannot be used, but Yafu is still better than plain ecm to automate the process, and keep track of found factors.)

The other day I started with 3 numbers with about 1600 digits, everything was working great, and I reached t30 without any problems.

Then I switched to numbers with about 1000-1020 digits, a few of them were all right, then problems began. On one number Yafu crashed with an "unrecognized character on input line" kind of error, on the next one with "too many allocs or frees" error. I'm not sure but it seems it happened when Yafu was about to start ecm.
The above was with Yafu-1.32.1 on linux (no external ecm), with the same version on Windows-7 Yafu crashed on the very first of these numbers (which Yafu on linux was able to process).

This is all happening in the batch mode, with "pretest -plan custom" and "-pretest_ratio" 0.02 or 0.03.
BTW, is there a way to tell Yafu to stop ecm on a particular fixed level, say t30, independent of the size of the input number? "-preset_ratio" works but it accepts only 2 fractional digits, if I try 0.025 it is converted to 0.03.
Even with preset_ratio accepting more fractional digits, an option like "preset_level t30" will be better.

Thanks!
Other people have reported problems when the input size is right around 1024 characters. Coincidentally, most of the character buffers in yafu are initialized to 1024 characters. They are supposed to grow as necessary, and given that 1600 digit inputs work they seem to be doing that, but it looks like there are issues when the inputs are close to the overflow point. I'll look into it.

There is no way that I know of to have yafu stop at a certain t-level, but I don't think it would be hard to add.

Thanks for the feedback.
bsquared is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Running YAFU via Aliqueit doesn't find yafu.ini EdH YAFU 8 2018-03-14 17:22
Where to report bugs Matt Software 1 2007-02-20 19:13
Possible Prime95 bugs JuanTutors Software 9 2006-09-24 21:22
RMA 1.7 beta bugs TTn 15k Search 2 2004-11-24 22:11
RMA 1.6 fixes LLR bugs! TTn 15k Search 16 2004-06-16 01:22

All times are UTC. The time now is 03:51.

Sun Apr 18 03:51:16 UTC 2021 up 9 days, 22:32, 0 users, load averages: 2.01, 2.04, 1.94

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.