Block Triangular Matrix/Examples/Arbitrary Example 1

Examples of Block Triangular Matrices

This $4 \times 4$ square matrix is an example of a $2 \times 2$ block upper triangular matrix wth $2 \times 2$ submatrices:

$\paren {\begin {array} {rr|rr} 1 & 2 & 5 & 4 \\ 1 & 1 & 1 & 2 \\ \hline 0 & 0 & -1 & 1 \\ 0 & 0 & 0 & 1 \end {array} }$

which is not an upper triangular matrix.

Sources

• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): block triangular matrix