\left[
\begin{array}{l}
x\\ y
\end{array}
\right]
*
\left[
\begin{array}{l}
x'\\ y'
\end{array}
\right]=
\left[
\begin{array}{cc}
x & Dy\\ y & x
\end{array}
\right]
\left[
\begin{array}{l}
x'\\ y'
\end{array}
\right]