On Mon, Sep 15, 2008 at 10:05 AM, phil <[EMAIL PROTECTED]> wrote: > > I've been pushing the limits of determinant calculation over > multivariate polynomial rings. I can calculate determinants of > matrices up to 9x9 of the form [[x_0_0, x_0_1],[x_1_0, x_1_1]] (each > element is a single unique variable). When I get to 10x10 is runs for > a while the crashes with: > 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).
How much RAM do you have? Write to me off list if you want access to a machine with more :-) > 9x9 matrices only take about 40 seconds. The 10x10 calculation runs > for a long time (>1 hr) before crashing. This is on 64 bit Ubuntu > with the patch in Trac #4068 (http://trac.sagemath.org/sage_trac/ > ticket/4068) applied. > BTW, what is the underlying algorithm used for the determinants? As > I understand it, the naive way is O(N!) while the recursive way is > O(N^3) for a NxN matrix. > Also, "occured" is misspelled in the error message. It should be > "occurred". > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
