2009/5/21 John Cremona <john.crem...@gmail.com>: > In 4.0.alpha0, this causes a segmentation fault: > > ---------------------------------------------------------------------- > | Sage Version 4.0.alpha0, Release Date: 2009-05-15 | > | Type notebook() for the GUI, and license() for information. | > ---------------------------------------------------------------------- > sage: K.<a>=NumberField(x^2-x+22) > sage: w=-13*a-14 > sage: E=EllipticCurve([0,0,0,0,-1728*w]) > sage: P1 = E.lift_x(-3*a-66) > sage: P2 = E.lift_x((-21*a-93)/4) > sage: P2.division_points(19)
It works fine to do sage: g = P2.division_points(19, poly_only=True) which defines a polynomial of degree 361 over Q(sqrt(-87)), but then g.roots() goes Boom. BTW, for this curve I needed to factor the 29-division polynomial (which has degree 420). That was very easy and quick (it is irreducible in fact) but in Magma I had givenup waiting (i.e. more than 10mins). > > > ------------------------------------------------------------ > Unhandled SIGSEGV: A segmentation fault occured in SAGE. > This probably occured because a *compiled* component > of SAGE has a bug in it (typically accessing invalid memory) > or is not properly wrapped with _sig_on, _sig_off. > You might want to run SAGE under gdb with 'sage -gdb' to debug this. > SAGE will now terminate (sorry). > ------------------------------------------------------------ > > John > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
