Wang, Zhirao

web-render

test the tex

A_{m\times n}=U_{m\times m}S_{m\times n}V_{n\times n}^T=U_{m\times m}
{\left (\begin{array}{cc}
    D_{r \times r}&O\\
    O&O
    \end{array}
    \right)}
V_{n\times n}^T

\begin{equation}
A_{m\times n}=U_{m\times m}S_{m\times n}V_{n\times n}^T=U_{m\times m}
{\left (\begin{array}{cc}
D_{r \times r}&O\\
O&O
\end{array}
\right)}
V_{n\times n}^T
\end{equation}