\begin{eqnarray*}
\X = \left( \begin{array}{ccccc}
            1 & x_{11} & x_{12} & \dots & x_{1q} \\
            1 & x_{21} & x_{22} & \dots & x_{2q} \\
            \vdots & \vdots & \vdots & \ddots & \vdots \\
            1 & x_{n1} & x_{n2} & \dots & x_{nq}  \\
            \end{array} \right).
\end{eqnarray*}
