ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Tue, 03 Dec 2013 17:05:46 +0100symbolic 2x2 block matrix inversionhttps://ask.sagemath.org/question/10799/symbolic-2x2-block-matrix-inversion/Is it possible in SAGE to get the 2x2 block matrix inversion described in [Wikipedia](https://en.wikipedia.org/wiki/Block_matrix_pseudoinverse#Block_matrix_inversion)?
I looked at [this question](http://ask.sagemath.org/question/3245/determinant-of-block-matrices) about the determinant of block matrices, and at [this question](http://ask.sagemath.org/question/505/symbolic-matrices) about symbolic matrices, and tried the following code on the [cloud](http://www.sagenb.org/):
A = matrix(SR, 2, 2, 'a1 a2 a3 a4'.split(' '))
B = matrix(SR, 2, 2, 'b1 b2 b3 b4'.split(' '))
C = matrix(SR, 2, 2, 'c1 c2 c3 c4'.split(' '))
D = matrix(SR, 2, 2, 'd1 d2 d3 d4'.split(' '))
M = block_matrix(SR, 2, 2, [A, B, C, D])
Mi = M.inverse()
Mi.simplify_rational()
But it doesn't seem to be able to exactly reproduce the Wikipedia formula (it returns a horrible formula full of a1, a2, etc). Any idea?timflutreTue, 03 Dec 2013 17:05:46 +0100https://ask.sagemath.org/question/10799/