fOblkdiag – IQClab

The function $C=fOblkdiag(A)$ generates the matrix

$C=\left(\begin{array}{cc}0&A\\A^T&0\end{array}\right).$

If specifying the second input (i.e., $C=fOblkdiag(A,B)$ ), where $B$ must be a square and symmetric matrix, the function yields the matrix

$C=\left(\begin{array}{ccc}0&0&A\\0&B&0\\A^T&0 &0 \end{array}\right).$

Finally, if also specifying the third input (i.e., $C=fOblkdiag(A,B,[a,b])$ ), with the nonnegative integers $a$ and $b$ , the function yields the matrix

$C=\left(\begin{array}{ccccc}0_{a\times a}&0&0&0&0\\0&0&0&A&0\\0&0&B&0&0\\0&A^T&0 &0 &0\\0&0&0&0&0_{b\times b}\end{array}\right).$