On Tue, Mar 4, 2008 at 11:20 PM, Andrey Y Novoseltsev <[EMAIL PROTECTED]> wrote: > Dear William, > > It seems that the following is definitely a bug - zero vector in the basis:
This is now trac #2398, and there is a patch there that fixes the problem. It was a somewhat subtle bug on "non random" input in the new vastly faster Hermite Normal Form code I wrote for Sage. Thanks for finding this and reporting it. This should be fixed also in sage-2.10.3, which will be released soon. > > ========================================== > sage: m = lattice_polytope.read_palp_matrix(r"""4 9 > ... 0 0 0 0 0 0 0 0 0 > ... 0 3 0 -2 1 -2 -2 1 -2 > ... 0 0 3 2 2 5 0 0 3 > ... 0 0 0 0 0 0 0 0 0""") > sage: m > [ 0 0 0 0 0 0 0 0 0] > [ 0 3 0 -2 1 -2 -2 1 -2] > [ 0 0 3 2 2 5 0 0 3] > [ 0 0 0 0 0 0 0 0 0] > sage: Ns = (ZZ^4).submodule(m.columns()) > sage: Ns > Free module of degree 4 and rank 2 over Integer Ring > Echelon basis matrix: > [0 0 0 0] > [0 1 0 0] > sage: Ns.basis() > [ > (0, 0, 0, 0), > (0, 1, 0, 0) > ] > sage: Ns.coordinates(m.column(0)) > Traceback (most recent call last): > ... > ValueError: self must be square > ========================================== > > The following is also quite strange for modules over integers: > > ========================================== > sage: Ns = (ZZ^4).submodule(m.columns()[:4]) > sage: Ns > Free module of degree 4 and rank 2 over Integer Ring > Echelon basis matrix: > [0 1 5 0] > [0 3 0 0] > sage: Ns.coordinates(m.column(2)) > [3/5, -1/5] > ========================================== > > I got it in the notebook while running the default version of sage on > sage.math > and will be very glad if this is easy to fix. > > Can I get an account on sagetrac so that I can quit bugging you about bugs? > Preferrred username is "novoselt" > > Thank you! > Andrey > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@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-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
