On Jul 13, 8:32 pm, William Stein <wst...@gmail.com> wrote: > Sage is probably just using some completely generic general > implementation of "kernel" for matrices.
Yes, that is correct. It's a totally generic routine and it stands a very good chance of giving an incorrect result with entries from RDF. The LU routine for RDF/CDF matrices uses the NumPy/SciPy libraries. At the moment, it only accepts square matrices, but with the positively-reviewed patch at http://trac.sagemath.org/sage_trac/ticket/10839 it will accept rectangular matrices. For an over-sized example, I get sage: M = matrix(RDF, 400, 400, lambda i,j: i+j) sage: time x = M.LU() Time: CPU 0.02 s, Wall: 0.02 s Rob -- 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 URL: http://www.sagemath.org
