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-   -   Factoring database (https://www.mersenneforum.org/showthread.php?t=11119)

gd_barnes 2009-06-13 20:43

[quote=henryzz;177465]the reason it does that is because it is more efficient to factor those numbers by using QS or GNFS than by ecm
for example to run 30 digit ecm on a c60 would take 15 minutes and probably find a factor but the number could be definitely(forgetting bugs in the program and such like:smile:) factored by QS in 5 minutes
the reason that you cannot use the database to factorize numbers above c85 is that it would clog up the database by taking an hour or more each
VHL disappears when it is judged that the optimal amount of ecm has been done and it is time to move to QS or for >~c90 GNFS
we are actually rather lucky with the database it does more ecm than many people would recommend on small numbers[/quote]

OK, I understand the reasoning now, having played around and watched the timing of Alpertron's applet when various size numbers move from ECM factoring to sieving.

So, the 2nd problem that I described is at least partially avoided by not allowing the sieving nor very high ECMing of ~87-95 digit numbers past the point at which it determines that sieving would take too long (perhaps > 1 hour) -and- yet sieving would still be more efficient then ECMing such that it should be done by one's self separate from the database workers. (That's a handful of a sentence. lol) Someone correct me if I'm wrong there.

BTW, I know nothing about what curves, B1's, or B2's exactly mean. I'm not asking anyone for an explanation as it is something that I need to study and learn myself. I see that there is plenty of information available and in the near future, I'll start digging into it. I just wanted everyone to know that while I'm a math enthusiast, I'm quite a newb at the factoring terminology.

I have to admit this is a fun diversion from the pressures of running 2 projects. :-)


Gary

henryzz 2009-06-13 21:05

[quote=gd_barnes;177483]BTW, I know nothing about what curves, B1's, or B2's exactly mean. I'm not asking anyone for an explanation as it is something that I need to study and learn myself. I see that there is plenty of information available and in the near future, I'll start digging into it. I just wanted everyone to know that while I'm a math enthusiast, I'm quite a newb at the factoring terminology.

I have to admit this is a fun diversion from the pressures of running 2 projects. :-)


Gary[/quote]
does this page answer any of your questions?
[url]http://www.loria.fr/~zimmerma/records/ecm/params.html[/url]

10metreh 2009-06-14 06:22

I don't know everything about how ECM works, but a "curve" is one ECM run, as it were. The B1 is the limit for "step 1", the B2 is the limit for "step 2". Each curve has a "sigma" which defines the curve as being different from all others with the same B1 and B2. The sigma changes for each curve, and a few sigmas under 2^32 (the GMP-ECM limit) will (hopefully) find a factor. The chances of finding this factor depends on how many there are, which is closely related to B1 and B2.

kar_bon 2009-06-16 15:08

The [b]40,000,000th[/b] id was entered in the Factoring Database: [url]http://factorization.ath.cx/search.php?id=40000000[/url]

BTW: A factor of the Aliquot Sequence 249780 index 547.

Andi_HB 2009-06-16 17:57

I have updated a lot of Numbers the last 2 weeks.
All tables that are called completed on the first page from Kamada are also completed in the Database now. :rolleyes:

Regards Andi_HB

Mini-Geek 2009-06-17 17:40

[quote=10metreh;177912]The database is having problems. I can't get it to display any numbers or sequences.[/quote]
I had the same problem, it started working again a while ago. Is it still down for anyone?

kar_bon 2009-06-17 23:49

yesterday i've reported the 40M factor-id in the database, and now: 300,000 more!

who, the hell, has inserted such an amount of factors there?

or is this due to the optimization?

Syd 2009-06-18 00:07

[QUOTE]I have updated a lot of Numbers the last 2 weeks.
All tables that are called completed on the first page from Kamada are also completed in the Database now.

Regards Andi_HB [/QUOTE]

:bow: Wow! Must have been a lot of work.

[QUOTE=kar_bon;177953]yesterday i've reported the 40M factor-id in the database, and now: 300,000 more!

who, the hell, has inserted such an amount of factors there?

or is this due to the optimization?[/QUOTE]

Dont know who inserted them, but new factors are always welcome, as long as they are not just random numbers

kar_bon 2009-06-18 00:12

[QUOTE=Syd;177955]Dont know who inserted them, but new factors are always welcome, as long as they are not just random numbers[/QUOTE]

like these here? [url]http://primes.utm.edu/lists/small/millions/[/url] :grin:

Andi47 2009-06-18 05:13

[QUOTE=Syd;177951]
Btw, what about a shorter domain?
[url]http://factordb.com/[/url][/QUOTE]

Caveat: The worker (linux AND windows versions) would have to be updated.

henryzz 2009-06-18 05:50

[quote=Andi47;177966]Caveat: The worker (linux AND windows versions) would have to be updated.[/quote]
not if we keep the old as well


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