Is there a straight-forward way to create a matrix from blocks? The Matrix.diag function is nice for creating a block diagonal matrix:
In [1]: Matrix.diag(2*eye(2),3*eye(3)) Out[1]: ⎡2 0 0 0 0⎤ ⎢ ⎥ ⎢0 2 0 0 0⎥ ⎢ ⎥ ⎢0 0 3 0 0⎥ ⎢ ⎥ ⎢0 0 0 3 0⎥ ⎢ ⎥ ⎣0 0 0 0 3⎦ I'd like to do something similar but for a general block matrix. I imagine something like: >>> Matrix.fromblocks([[eye(2),2*eye(2)],[3*eye(2),4*eye(2)]]) The expected output would be: [1 0 2 0] [0 1 0 2] [3 0 4 0] [0 3 0 4] This almost works if I pass a list of matrices to the Matrix constructor: In [5]: Matrix([eye(2), eye(2)]) Out[5]: ⎡1 0⎤ ⎢ ⎥ ⎢0 1⎥ ⎢ ⎥ ⎢1 0⎥ ⎢ ⎥ ⎣0 1⎦ It doesn't work if I try to concatenate horizontally though: In [7]: Matrix([[eye(2), eye(2)]]) Out[7]: ⎡⎡1 0⎤ ⎡1 0⎤⎤ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎣⎣0 1⎦ ⎣0 1⎦⎦ Same happens if I try to do both: In [8]: Matrix([[eye(2), eye(2)], [eye(2), eye(2)]]) Out[8]: ⎡⎡1 0⎤ ⎡1 0⎤⎤ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎢⎣0 1⎦ ⎣0 1⎦⎥ ⎢ ⎥ ⎢⎡1 0⎤ ⎡1 0⎤⎥ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎣⎣0 1⎦ ⎣0 1⎦⎦ I see that there is a BlockMatrix class but I don't want a block matrix. I want to construct a normal matrix from blocks (similar to diag). There is a deblock function but it doesn't do what I hoped: In [13]: from sympy.matrices.expressions.blockmatrix import deblock In [14]: deblock(Matrix([[eye(2), eye(2)], [eye(2), eye(2)]])) Out[14]: ⎡⎡1 0⎤ ⎡1 0⎤⎤ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎢⎣0 1⎦ ⎣0 1⎦⎥ ⎢ ⎥ ⎢⎡1 0⎤ ⎡1 0⎤⎥ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎣⎣0 1⎦ ⎣0 1⎦ In [15]: deblock(BlockMatrix([[eye(2), eye(2)], [eye(2), eye(2)]])) Out[15]: ⎡⎡1 0⎤ ⎡1 0⎤⎤ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎢⎣0 1⎦ ⎣0 1⎦⎥ ⎢ ⎥ ⎢⎡1 0⎤ ⎡1 0⎤⎥ ⎢⎢ ⎥ ⎢ ⎥⎥ ⎣⎣0 1⎦ ⎣0 1⎦⎦ Am I missing a similar way to do this? -- Oscar -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAHVvXxTUe8Qtu1YGzcKWtR7Q_SXfOrenxqYORE_i6hCS8VnMuA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
