Mersenne Digest Wednesday, November 1 2000 Volume 01 : Number 789 ---------------------------------------------------------------------- Date: Mon, 30 Oct 2000 12:36:12 +0000 From: Gordon Spence <[EMAIL PROTECTED]> Subject: Mersenne: Re: Output from nofactor.cmp >On Mon, 30 Oct 2000 Henk Stokhorst wrote >Subject: Mersenne: bug in Wordpad? > >L.S., > >Whenever I have a large file (about 3.000 lines) with exponents to test >(extracted from the nofactor.cmp file) and replace all the 'Test=' with >'Factor=' using wordpad (part of windows accesoires) one line gets to >read 'Factorst='. When I extract items from this file using decomp.exe from George, then ALL of the lines already say Factor= How are you extracting them? regards G _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Mon, 30 Oct 2000 07:43:09 -0800 From: "John R Pierce" <[EMAIL PROTECTED]> Subject: Re: Mersenne: bug in Wordpad? > It is not really the OS (although UNIX does have a lot of nice tools for > this type of thing) it is wordpad that is not really the most capable text > editor. > > If you are using Windows I would suggest you try TextPad which is available > for 30 day evaluation from www.textpad.com. another very good ascii editor is 'Ultraedit32', also available for free evaluation. http://www.ultraedit.com - -jrp _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Mon, 30 Oct 2000 18:22:29 +0100 From: "Steinar H. Gunderson" <[EMAIL PROTECTED]> Subject: Mersenne: Re: bug in Wordpad? On Mon, Oct 30, 2000 at 07:43:09AM -0800, John R Pierce wrote: >another very good ascii editor is 'Ultraedit32', also available for free >evaluation. >http://www.ultraedit.com While EditPad (http://www.editpad.com/, I think, not quite sure) is postcardware (ie. send a postcard to the author :-) ). Optionally, if you're into Unix and vi, vim (www.vim.org) is of course available in DOS and Windows versions :-) /* Steinar */ - -- Homepage: http://members.xoom.com/sneeze/ _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Mon, 30 Oct 2000 19:18:24 +0100 From: Henk Stokhorst <[EMAIL PROTECTED]> Subject: Re: Mersenne: Re: Output from nofactor.cmp Gordon Spence wrote: > When I extract items from this file using decomp.exe from George, then ALL > of the > lines already say Factor= > How are you extracting them? with the wrong parameter, -t instead of -w ;-) YotN, Henk Stokhorst _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Tue, 31 Oct 2000 10:42:11 +0100 From: "Hoogendoorn, Sander" <[EMAIL PROTECTED]> Subject: RE: Mersenne: bug in Wordpad? > Whenever I have a large file (about 3.000 lines) with > exponents to test > (extracted from the nofactor.cmp file) and replace all the > 'Test=' with > 'Factor=' using wordpad (part of windows accesoires) one line gets to > read 'Factorst='. You can extract with the -w option to get Factor= infront of each line see the readme file _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Tue, 31 Oct 2000 11:16:00 +0000 From: Alexander Kruppa <[EMAIL PROTECTED]> Subject: Mersenne: ECM better than O(sqrt(f)) ? I've read on the list some time ago that ECM takes, like Pollard-Rho or P-1, O(sqrt(f)) operations mod N to find a factor f. But looking at the factors found so far I find that hard to believe; according to that formula, finding a 50-digit factor should be 10^15 times harder than finding a 20-digit factor. Even if a 20-digit could be found in 1 sec. average, the 50-digit would take some 30 million years - I dont believe this much time has been spent on ECM worldwide already. Is ECM better than O(sqrt(f)) ? Are there any more accurate lower bounds, or even a \Theta(g(f)) ? Ciao, Alex. _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Tue, 31 Oct 2000 03:51:53 -0800 From: Paul Leyland <[EMAIL PROTECTED]> Subject: RE: Mersenne: ECM better than O(sqrt(f)) ? > I've read on the list some time ago that ECM takes, like > Pollard-Rho or > P-1, O(sqrt(f)) operations mod N to find a factor f. But > looking at the > factors found so far I find that hard to believe; according to that And quite right too. It's just plain wrong. ECM runs in sub-exponential time. > formula, finding a 50-digit factor should be 10^15 times harder than > finding a 20-digit factor. Even if a 20-digit could be found in 1 sec. > average, the 50-digit would take some 30 million years - I > dont believe > this much time has been spent on ECM worldwide already. > Is ECM better than O(sqrt(f)) ? Are there any more accurate lower > bounds, or even a \Theta(g(f)) ? The expected number of arithmetic operations taken to find a prime factor p is asymptotic to exp(sqrt(log p log log p)) and so is, in some handwaving manner, halfway between polynomial and exponential. Of course, as N gets larger the cost of each operation gets larger, but at a strictly polynomial rate for any sane implementation of multiple precision arithmetic. Paul p.s. I found a 50-digit factor by ECM recently 8-) _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Tue, 31 Oct 2000 23:02:03 -0000 From: "Andrew Gibbons" <[EMAIL PROTECTED]> Subject: RE: Mersenne: bug in Wordpad? Hi Henk, A year or so ago I discovered that there was a bug in one of the dlls that WordPad uses. The dll comes in many versions and is the Rich Edit Control. The bug occured whenever text was replaced at a particular boundary (64k I think). It didn't happen with the old version I was using but did with a newer version my beta tester was using. I don't know if it has now being fixed... It actually showed up in a Delphi program I was writing but, of course, should show up in a program that 'hits the spot'. Regards Andrew Gibbons _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ Date: Wed, 1 Nov 2000 18:17:51 -0500 (EST) From: "David A. Miller" <[EMAIL PROTECTED]> Subject: Mersenne: ECM update -- M727 finished up to 50 digits The last machine that I had working on M727 has finished its 1000 curves at B1=44M. This is enough to finish the recommended number of curves at that bound. Thus there are probably no factors below 10^50, and it won't be practical to find the factors with ECM. Have any other numbers received as much ECM effort as this? I'm betting that there aren't many. David A. Miller [EMAIL PROTECTED] _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt ------------------------------ End of Mersenne Digest V1 #789 ******************************
