mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Factoring

Reply
 
Thread Tools
Old 2018-01-12, 15:25   #1
vasyannyasha
 
vasyannyasha's Avatar
 
"Vasiliy"
Apr 2017
Ukraine

6010 Posts
Default My luck

I didn't find 12-digit factor after 1000 curves with B1=11000
What are the odds?

Last fiddled with by vasyannyasha on 2018-01-12 at 15:25 Reason: too many zeros
vasyannyasha is offline   Reply With Quote
Old 2018-01-12, 17:10   #2
firejuggler
 
firejuggler's Avatar
 
Apr 2010
Over the rainbow

24×3×72 Posts
Default

what number did you test?
firejuggler is offline   Reply With Quote
Old 2018-01-12, 17:18   #3
vasyannyasha
 
vasyannyasha's Avatar
 
"Vasiliy"
Apr 2017
Ukraine

22·3·5 Posts
Default

111-digit number from aliquot sequence
vasyannyasha is offline   Reply With Quote
Old 2018-01-12, 17:20   #4
vasyannyasha
 
vasyannyasha's Avatar
 
"Vasiliy"
Apr 2017
Ukraine

22·3·5 Posts
Default

GMP-ECM write only about odds for 35-digit factor and bigger.
vasyannyasha is offline   Reply With Quote
Old 2018-01-12, 17:38   #5
VictordeHolland
 
VictordeHolland's Avatar
 
"Victor de Hollander"
Aug 2011
the Netherlands

23×3×72 Posts
Default

Assuming you're testing a number in a normal range (100-400 digits)

With GMP-ECM
t20 = 86 curves with B1=11,000 B2=1,873,422
1000 curves = more than 11 x t20
So after 1000 curves you should've found a 20 digit factor 11 times on average.
Chance to miss a 20 digit factor after 1000 curves is very small
e^(-11) = ~ 0.0000167 = 0.00167%

Are you sure your software has compiled ok? Is the memory ok?

Willing to share the number in question? So we can run a couple of hundred curves to check if GMP-ECM finds the factor on different hardware?

Last fiddled with by VictordeHolland on 2018-01-12 at 17:50 Reason: number?
VictordeHolland is offline   Reply With Quote
Old 2018-01-12, 17:52   #6
vasyannyasha
 
vasyannyasha's Avatar
 
"Vasiliy"
Apr 2017
Ukraine

22×3×5 Posts
Default

Before this I find dozens of different factors with ECM.
Memory work fine.
Maybe this was bug for 30 seconds.
After this P-1 test used 2 GB and find this factor.

Last fiddled with by vasyannyasha on 2018-01-12 at 18:02 Reason: My English
vasyannyasha is offline   Reply With Quote
Old 2018-01-13, 17:51   #7
WraithX
 
WraithX's Avatar
 
Mar 2006

23·59 Posts
Default

Quote:
Originally Posted by VictordeHolland View Post
Assuming you're testing a number in a normal range (100-400 digits)

With GMP-ECM
t20 = 86 curves with B1=11,000 B2=1,873,422
1000 curves = more than 11 x t20
So after 1000 curves you should've found a 20 digit factor 11 times on average.
Chance to miss a 20 digit factor after 1000 curves is very small
e^(-11) = ~ 0.0000167 = 0.00167%

Are you sure your software has compiled ok? Is the memory ok?

Willing to share the number in question? So we can run a couple of hundred curves to check if GMP-ECM finds the factor on different hardware?
According to my new web page, the chance to miss a 12 digit factor after 1000 curves at B1=11e3 is around 2.304 * 10^-203. My page shows 81e-6 (about 0.000081 or 0.0081%) to miss a 20-digit factor after 1000 curves at B1=11e3.

I think the differences in our numbers stems from GMP-ECM v7 recommending 106.7632 curves to find a 20-digit factor with B1=11e3 with param=1. I think you might be using param=0.

You can read more about my web page to calculate ecm success/failure chances here:
http://www.mersenneforum.org/showthread.php?t=22924

Last fiddled with by WraithX on 2018-01-13 at 17:53
WraithX is offline   Reply With Quote
Old 2018-01-13, 18:28   #8
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(3,3^1118781+1)/3

2×13×347 Posts
Default

Quote:
Originally Posted by vasyannyasha View Post
I didn't find 12-digit factor after 1000 curves with B1=11000
What are the odds?
Rhetorical questions require rhetorical answers.
If your darts do not hit the dart board, the odds are that there could be a problem with darts, or with the dart board, or with the air between the darts and the darts board, or with the thrower of darts. (In no particular order.)
Batalov is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Planet closing in causing my family's bad luck ? science_man_88 Astronomy 16 2010-09-21 03:44

All times are UTC. The time now is 00:15.

Sat May 30 00:15:51 UTC 2020 up 65 days, 21:48, 1 user, load averages: 1.81, 1.82, 1.65

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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.