That will be really easy to implement, I'll do it right now. - Robert
On Jan 8, 2008, at 11:25 PM, Mike Hansen wrote: > It was my impression that he didn't want a matrix with matrix entries, > but instead wanted the matrix whose entries were given by the entries > of the submatrices. > > --Mike > > On Jan 8, 2008 11:12 PM, William Stein <[EMAIL PROTECTED]> wrote: >> >> On Jan 8, 2008 11:05 PM, [EMAIL PROTECTED] >> <[EMAIL PROTECTED]> wrote: >>> >>> >>> >>> On Jan 9, 7:43 am, "William Stein" <[EMAIL PROTECTED]> wrote: >>> >>>> On Jan 8, 2008 4:27 AM, vgermrk <[EMAIL PROTECTED]> wrote: >>>> >>>> >>>> >>>>> Is there a way to construct block matrices in SAGE? >>>>> Not just the "block_sum", "augment" and "stack" functions. >>>> >>>>> As an example, let A, B, C, D be matrices and i want to >>>>> construct a >>>>> matrix like E=[[A,B],[C,D]] >>>> >>>>> Such a feature would be very nice. >>>> >>>> Sage's MatrixSpace and matrix don't have support for this. >>>> numpy (which you get via "import numpy") might have support >>>> for numerical matrices like this. >>> >>> CVXOPT also has support for this: >>> http://abel.ee.ucla.edu/cvxopt/examples/short-examples/creating- >>> matrices/ >> >> And, just to be clear, CVXOPT is standard in Sage. >> >> There are a number of caveats though. Currently you really have >> to switch >> to python mode to create a cvxopt matrix in Sage, probably because of >> preparser issues (see below). Also, more importantly, it looks to me >> like making a matrix from matrices in CVXOPT does *not* make a matrix >> with matrix entries, but instead makes a single matrix -- see below. >> >> >> {{{id=0| >> %python >> >> from cvxopt.base import matrix >> A = matrix([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], (2,3)) >> print A >> /// >> 1.0000e+00 3.0000e+00 5.0000e+00 >> 2.0000e+00 4.0000e+00 6.0000e+00 >> }}} >> >> {{{id=1| >> %python >> >> B = matrix([ [1.0, 2.0], [3.0, 4.0] ]) >> print B >> /// >> 1.0000e+00 3.0000e+00 >> 2.0000e+00 4.0000e+00 >> }}} >> >> {{{id=2| >> %python >> >> a = matrix([ [A] ,[B] ]) >> }}} >> >> {{{id=4| >> print a >> /// >> 1.0000e+00 3.0000e+00 5.0000e+00 1.0000e+00 3.0000e+00 >> 2.0000e+00 4.0000e+00 6.0000e+00 2.0000e+00 4.0000e+00 >> >> }}} >> >>> >> > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@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-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
