Partitioned matrices | What works and what doesn't

Partitioned matrices | What works and what doesn't

It’s often useful to partition a matrix, thinking of it as a matrix whose entries are matrices. For example, you could look at the matrix 6 × 6 as a 2 × 2 matrix whose entries are 3 × 3 matrices. M is not a diagonal matrix of real numbers, but its block structure is a diagonal matrix of blocks. It might be possible in some application to take advantage of the fact that the off-diagonal blocks are zero matrices. You can multiply two partitioned m…