On Jul 15, 9:10 am, Henry de Valence <[email protected]> wrote: > Thanks -- I'll look into the process of writing a patch over the > weekend.
Rather than try to implement kernels over inexact rings, I suspect you would be better off using an LU decomposition for an RDF/CDF matrix and making your own decisions on where the zero's lie. You could pad with zero rows or columns until the patch allowing rectangular matrices gets merged. > Also, is there a way to profile the time Sage is spending while it's > computing the kernel? Trying to find the kernel of rational matrices, I > get strange results: You can try doing sage: set_verbose(1) before computing the kernels, and you will get some timing information. The internal organization (not the algorithms) of kernel computations will change in the next release, and the "verbose" commands may be a bit more informative then. There will also be a "right_kernel_matrix()" command that will avoid the overhead of creating a vector space, though I suspect that is negligible in the examples you are working with. Over QQ kernel computations eventually end up in the Integer Matrix Library (IML) routines, if remember right, which are generally quite fast. Rob -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
