## Version 1.0.0

12th July 2004

Recent Changes

• Single
• Double
• Single Complex
• Double Complex

### MC25: Permute a sparse matrix to block triangular form

Permutes a sparse real or complex matrix to a block lower triangular form, i.e. given a sparse matrix $$\mathbf{A} = {\{a _{ij}\}} _{n \times n}$$, it attempts to find permutation matrices $$\mathbf{P}$$ and $$\mathbf{Q}$$ such that $$\mathbf{\hat{A}} = \mathbf{PAQ}$$ is block lower triangular and it returns $$\mathbf{\hat{A}}$$ to the caller.