On Jun 7, 10:29 pm, Rob Beezer <goo...@beezer.cotse.net> wrote: > I would be in favor of a right kernel matrix having its vectors as > columns. It looks like this would save some transposes on the exit from > the actual routines doing the computations.
That would be the *ONLY* reason. In general it seems that Sage vectors have a slight preference to being row vectors (if you pass "matrix" a list of vectors, they are interpreted as rows), so returning a matrix with the appropriate row space is quite defendable. Sage vectors are a bit ambivalent towards their orientation as can be seen how they behave wrt multiplication on either side of a matrix. For applications of right_kernel_matrix, it's a complete toss-up whether you need the rows or the transpose of that. Kernels are just as often used to find a complement of a subspace as they are to compute a matrix with prescribed (left)kernel. So, we should just do what is most efficient, subject to being consistent. (In fact I ran into the fact that left_kernel_matrix was missing because I wanted to compute a matrix with prescribed right kernel) -- 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
