mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Factoring

Reply
 
Thread Tools
Old 2021-06-29, 18:18   #397
EdH
 
EdH's Avatar
 
"Ed Hall"
Dec 2009
Adirondack Mtns

411210 Posts
Default

Quote:
Originally Posted by EdH View Post
Thanks! I'm wondering what I did here. Looking at the SNFS params file, it's all messed up. There's no side choice, the values are all wrong and even the siever was wrong (I =12). I suppose I'm lucky it found relations. I'm going to go back to sleep for a while. I'll post the factors for the c156 later, but then I think I'll take a break for a bit.
Well, actually, it wasn't as bad as I thought. I was looking at the wrong params file. I found the correct one that I used (even has I = 14), but I see I didn't tell it the rational side. Does it default to algebraic?

Edit: I'm still going to take a break. . .

Last fiddled with by EdH on 2021-06-29 at 18:19
EdH is offline   Reply With Quote
Old 2021-06-30, 00:19   #398
charybdis
 
charybdis's Avatar
 
Apr 2020

54710 Posts
Default

Quote:
Originally Posted by EdH View Post
Well, actually, it wasn't as bad as I thought. I was looking at the wrong params file. I found the correct one that I used (even has I = 14), but I see I didn't tell it the rational side. Does it default to algebraic?
Yes it does, as it is geared towards GNFS. You need tasks.sieve.sqside = 0 to make it sieve on the rational side.
charybdis is offline   Reply With Quote
Old 2021-06-30, 02:17   #399
EdH
 
EdH's Avatar
 
"Ed Hall"
Dec 2009
Adirondack Mtns

24×257 Posts
Default

Quote:
Originally Posted by charybdis View Post
Yes it does, as it is geared towards GNFS. You need tasks.sieve.sqside = 0 to make it sieve on the rational side.
I've gotten in the habit of automating too many things with scripts. When I go back to manual, I forget things, especially when they are in the basic params files..

On the positive side, line 243 (12, 5) is finished:
Code:
c156 = p76 * p80
CADO-NFS failed, but Msieve picked up the slack.
EdH is offline   Reply With Quote
Old 2021-06-30, 23:08   #400
wombatman
I moo ablest echo power!
 
wombatman's Avatar
 
May 2013

178510 Posts
Default

Finally, after much help from Max and EdH, the C151 from (1,10) has factored as:

Code:
p60 factor: 184806081306587174940291557245764342530914498190952548289121
p92 factor: 35962122580466008384842772124308061023691332262402425391674828016485830052008927622384358809
wombatman is offline   Reply With Quote
Old 2021-07-07, 15:10   #401
wombatman
I moo ablest echo power!
 
wombatman's Avatar
 
May 2013

3·5·7·17 Posts
Default

The C177 from (12,4) is done:

Code:
p83 factor: 43946310278493822373729067976053173025156013123463695922015864334758076849073761041
p94 factor: 3879640675160979541328532833157840602964785213307428969835564939629208135592552250176921248367
wombatman is offline   Reply With Quote
Old 2021-07-08, 05:09   #402
Max0526
 
"Max"
Jun 2016
Toronto

2·3·151 Posts
Default Line 267 (13, 2) c212/snfs215 spun polys

+14.9%, very close E scores, for wombatman:
Code:
Line 1 : {'c4': '1', 'c3': '7', 'c2': '5', 'c1': '-16', 'c0': '64', 'Y1': '153443351011967263650109090408988092843096902070532823', 'Y0': '-222358410695752773704977506927634107778181446784947235'}

n: 17873511698719975553546839954709137037459623697774949935190855326681314654792125918183280261300300131118173299615880026661215517855797978119793793364567239265920670232618711404798034230366064418810273389844468661
# e = 4.06899674e-13
skew: 2.40753
type: snfs
c4: 1
c3: 7
c2: 5
c1: -16
c0: 64
Y1: 153443351011967263650109090408988092843096902070532823
Y0: -222358410695752773704977506927634107778181446784947235

Line 2 : {'c4': '1', 'c3': '11', 'c2': '32', 'c1': '19', 'c0': '61', 'Y1': '153443351011967263650109090408988092843096902070532823', 'Y0': '-68915059683785510054868416518646014935084544714414412'}

n: 17873511698719975553546839954709137037459623697774949935190855326681314654792125918183280261300300131118173299615880026661215517855797978119793793364567239265920670232618711404798034230366064418810273389844468661
# e = 4.0682386e-13
skew: 1.93206
type: snfs
c4: 1
c3: 11
c2: 32
c1: 19
c0: 61
Y1: 153443351011967263650109090408988092843096902070532823
Y0: -68915059683785510054868416518646014935084544714414412

Line 3 : {'c4': '4', 'c3': '14', 'c2': '5', 'c1': '-8', 'c0': '16', 'Y1': '306886702023934527300218180817976185686193804141065646', 'Y0': '-222358410695752773704977506927634107778181446784947235'}

n: 17873511698719975553546839954709137037459623697774949935190855326681314654792125918183280261300300131118173299615880026661215517855797978119793793364567239265920670232618711404798034230366064418810273389844468661
# e = 4.03902555e-13
skew: 1.20277
type: snfs
c4: 4
c3: 14
c2: 5
c1: -8
c0: 16
Y1: 306886702023934527300218180817976185686193804141065646
Y0: -222358410695752773704977506927634107778181446784947235

Line 4 : {'c4': '1', 'c3': '3', 'c2': '-10', 'c1': '-9', 'c0': '79', 'Y1': '153443351011967263650109090408988092843096902070532823', 'Y0': '-375801761707720037355086597336622200621278348855480058'}

n: 17873511698719975553546839954709137037459623697774949935190855326681314654792125918183280261300300131118173299615880026661215517855797978119793793364567239265920670232618711404798034230366064418810273389844468661
# e = 4.02131619e-13
skew: 2.82906
type: snfs
c4: 1
c3: 3
c2: -10
c1: -9
c0: 79
Y1: 153443351011967263650109090408988092843096902070532823
Y0: -375801761707720037355086597336622200621278348855480058

Line 5 : {'c4': '1', 'c3': '3', 'c2': '-13', 'c1': '-36', 'c0': '4', 'Y1': '403982966464462210316252132012441191942389341107175384', 'Y0': '-26288591585073291199340584499937889471048826204702885'}

n: 17873511698719975553546839954709137037459623697774949935190855326681314654792125918183280261300300131118173299615880026661215517855797978119793793364567239265920670232618711404798034230366064418810273389844468661
# e = 3.96927973e-13
skew: 0.98956
type: snfs
c4: 1
c3: 3
c2: -13
c1: -36
c0: 4
Y1: 403982966464462210316252132012441191942389341107175384
Y0: -26288591585073291199340584499937889471048826204702885
Max0526 is offline   Reply With Quote
Old 2021-07-22, 09:40   #403
Brownfox
 
Brownfox's Avatar
 
Dec 2017

71 Posts
Default

What rules of thumb are people using to decide how much ECM to do before embarking on NFS?


For instance, the last composite for (6,10) is a c177 for GNFS, or a c209 for SNFS Quartic. I've done ECM up to 50 digits (7556 curves at B1=43E6). Is this sufficient or would you expect some curves at 55 digit level?
Brownfox is offline   Reply With Quote
Old 2021-07-22, 12:09   #404
thyrex
 
Jun 2021

24 Posts
Default

In most cases, very large numbers have only two prime co-factors. If computer resources allow you to run stage t55 (B1 = 110M), you can go it. But there is very little chance of finding a co-factor at this stage, although it's possible. Otherwise, you can immediately proceed to the NFS stage.

As for me now I ran preNFS stage for c163 at point (2, 11) and c162 at point (5, 11). It take nearly 4 days for both on my computer.

c168 at point (9, -7) and c169 at point (10, -10) really ready for GNFS after t50.
thyrex is offline   Reply With Quote
Old 2021-07-22, 12:17   #405
charybdis
 
charybdis's Avatar
 
Apr 2020

10438 Posts
Default

Quote:
Originally Posted by Brownfox View Post
For instance, the last composite for (6,10) is a c177 for GNFS, or a c209 for SNFS Quartic. I've done ECM up to 50 digits (7556 curves at B1=43E6). Is this sufficient or would you expect some curves at 55 digit level?
As an SNFS job this is probably equivalent to a GNFS in the low 160s. I've seen a few different estimates for ECM effort but for GNFS I usually go for c*digits with c = 0.31 or 0.32. For this number, that would mean t50, maybe with a few additional curves at the t55 level.

For the c168 and c169 that thyrex mentions I'd run about a third of a t55.
charybdis is offline   Reply With Quote
Old 2021-07-22, 12:47   #406
thyrex
 
Jun 2021

100002 Posts
Default

Quote:
Originally Posted by charybdis View Post
For the c168 and c169 that thyrex mentions I'd run about a third of a t55.
when stage t50 was completed for these numbers immediately started preNFS stage.
thyrex is offline   Reply With Quote
Old 2021-07-22, 13:59   #407
charybdis
 
charybdis's Avatar
 
Apr 2020

10438 Posts
Default

What do you mean by "preNFS"?
charybdis is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
factoring 2ⁿ-2 equivalent to factoring 2ⁿ-1(I think) baih Miscellaneous Math 9 2020-09-21 07:11
OpenCL GPU P-1 Factoring and ECM Factoring xx005fs GPU Computing 3 2018-10-27 14:49

All times are UTC. The time now is 07:44.


Mon Dec 6 07:44:40 UTC 2021 up 136 days, 2:13, 0 users, load averages: 1.48, 1.52, 1.41

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.