Corrections to “A New Efficient Unconditionally Stable Finite-Difference Time-Domain Solution of the Wave Equation” [Jun 17 3114-3121]

In [1], $r_{x}$ , $r_{y}$ , and $\textbf {G}_{\textbf {M}}$ were mistyped. The correct values are \begin{align*} r_{x}=&\frac {\sqrt {2} \Delta t}{\sqrt {\varepsilon \mu } \Delta x} \sin {\left ({\frac { k_{x} \Delta x}{2} }\right )}\\ r_{y}=&\frac {\sqrt {2} \Delta t}{\sqrt {\varepsilon \mu } \Delta y} \sin {\left ({\frac { k_{y} \Delta y}{2} }\right )}\\ \mathbf {G_{M}}=&\begin{matrix} \left [{ \begin{matrix} \big (1+r_{x}^{2}\big )(\xi ^{2}+1)-2\xi &\quad -(2r_{x} r_{y}) \xi \\ -(2r_{x} r_{y}) \xi &\quad \big (1+r_{y}^{2}\big )(\xi ^{2}+1)-2\xi \end{matrix} }\right ]. \end{matrix} \end{align*}