On Jul 22, 2008, at 12:27 PM, Harald Schilly wrote:
> > On Jul 21, 10:50 pm, Tim Lahey <[EMAIL PROTECTED]> wrote: >> Lastly, if the ability to work with symbolic vectors/matrices was >> added, >> a nice thing to have would be to work with partitioned matrices and >> vectors. For example: >> >> A = [[ B, C],[D, E]] >> >> where B, C, D, and E are general sub-matrices. > > Look at block_matrix: > > sage: A = matrix(QQ, 2, 2, [3,9,6,10]) > sage: block_matrix([A, -A, ~A, 100*A]) > [ 3 9| -3 -9] > [ 6 10| -6 -10] > [-----------+-----------] > [-5/12 3/8| 300 900] > [ 1/4 -1/8| 600 1000] > Thanks, Harald. But I was talking about in the more general sense that B, C, D, and E are general (unknown elements) matrices at the time of manipulation. Many manipulations that are simple to do by hand have little to no support in various CAS programs. Partitioned matrices happen to be one of them. Others include: differentiation with respect to a function (I get around that in Maple by doing a substitution with a symbol and then reversing the substitution), derivatives with respect to a vector (mentioned before in this thread), and Calculus of Variations (I've done work on implementing some of it in Maple). --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
