Factoring database

[gd_barnes]

Originally Posted by henryzz

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) 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

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]

Originally Posted by gd_barnes

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

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

[10metreh]

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]

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

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

[Andi_HB]

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

[Mini-Geek]

Originally Posted by 10metreh

The database is having problems. I can't get it to display any numbers or sequences.

I had the same problem, it started working again a while ago. Is it still down for anyone?

[kar_bon]

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]

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

Wow! Must have been a lot of work.

Originally Posted by kar_bon

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?

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

[kar_bon]

Originally Posted by Syd

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

like these here? http://primes.utm.edu/lists/small/millions/

[Andi47]

Originally Posted by Syd

Btw, what about a shorter domain?
http://factordb.com/

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

[henryzz]

Originally Posted by Andi47

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

not if we keep the old as well