Oh, no, not this one again! I overhauled the elementary divisors code a while ago and I thought I had sorted out this one. Personally I feel that M.elementary_divisors() should always return a list of size min (M.nrows(), M.ncols()), which should also be the size of the square matrix output by M.smith_form().
I don't think it's a left/right issue; it's just that there are loads of different implementations of elementary_divisors depending on the base ring (as with just about everything in the matrix code), and elementary divisors over a field is a pretty vacuous concept anyway, so I must have missed it when I was checking for consistency. David On Dec 8, 12:16 pm, Harald Schilly <harald.schi...@gmail.com> wrote: > Hello, from the "report a problem" link I got the complaint that > elementary_divisors() is wrong. It turned out that it behaves > differently with respect to the matrix's ring. I guess it's one of > those left/right issues. > > Examples: > > sage: M = random_matrix(ZZ, 5,3) > sage: M.elementary_divisors() > [1, 1, 1, 0, 0] > > sage: M = random_matrix(QQ, 5,3) > sage: M.elementary_divisors() > [1, 1, 1] > > Can we make this more consistent? Ideas? The original request was to > change elementary_divisors() for ZZ matrices in the way so that it > returns 3 elements, not 5. > > H -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
