On Dec 16, 2008, at 07:17 , William Stein wrote:
> > On Tue, Dec 16, 2008 at 12:50 AM, achrzesz <achrz...@wp.pl> wrote: >> >> Hallo, >> I'm wondering what goes wrong with tis: >> >> (sage 3.2 compiled from sources, ubuntu 8.04, quad core 2.4 GHz) >> >> >> sage: for k in range(14,21): >> ....: f=2^2^k+1;w=ecm.find_factor(f);[w[0],prod(w)==f] >> ....: >> [2, False] >> [523923, False] >> [1901173, False] >> [2, False] >> [2, False] >> [30539, False] >> [2, False] >> >> Are the exponents to big? >> >> Andrzej Chrzeszczyk > > Yes, I think there must be a hard limit on the input line for GMP-ECM. > If I try the first number directly on the command line, it says > "Factor found in step 1: 2". However the first number is *odd*, so 2 > can't be a factor! > What's really happening is that GMP-ECM is ignoring everything after > the first 4095 digits when I paste the input in. I think you are running into a system limit, not an ECM limit. Even emacs seems to have a problem when I paste in "2^2^14+1". I finally got this to work by doing f = open("/tmp/foo", "w") print >> f, 2^2^14+1 f.close() in Sage, and then ecm < /tmp/foo in the shell: $ ecm 10000000 100000 < /tmp/foo GMP-ECM 6.1.3 [powered by GMP 4.2.1] [ECM] Input number has 4933 digits Using B1=10000000, B2=100000, polynomial x^1, sigma=3668583302 ... It's likely that the "expect" interface is running into the same limit, since it uses the tty sub-system. All those "bings" are a signal from the system (tty driver) that it's choking, and isn't reading what you are throwing at it. HTH Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Absorption of Federal Funds -------- If you're not confused, You're not paying attention -------- --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---