Hook block matrices into matrix(...) command

[robertwb]

Add the ability to access the functionality of #1732 to the default matrix(...) constructor.

Component: linear algebra

Reviewer: Marc Mezzarobba

Issue created by migration from https://trac.sagemath.org/ticket/1755

[black-stones]

comment:6

This is already implemented as block_matrix()

sage: A = random_matrix(ZZ, 2)
sage: B = random_matrix(ZZ, 2)
sage: C = random_matrix(ZZ, 2)
sage: D = random_matrix(ZZ, 2)
sage: block_matrix( [[A, B], [C, D]] )
[  1  -3| -1  -1]
[  0   0|  1   1]
[-------+-------]
[  0   0| -5   1]
[ -1   0|-10  31]

I don't think matrix() should create block matrices. It's possible that one would want a matrix of matrices rather than to merge the matrices together.

[mezzarobba]

Reviewer: Marc Mezzarobba

[embray]

comment:8

Presuming these are all correctly reviewed as either duplicate, invalid, or wontfix.