# small 3x3 matrix/picture/table with dots

I want to create some sort of arrangement of small(!) dots (some filled, some not) in a 3x3 shape like this

Has anyone an idea how to do this?

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$\begin{matrix} \circ & \bullet & \circ \\ \bullet & \bullet & \bullet \\ \circ & \bullet & \circ \end{matrix}$
\end{document}


Starting with Ignasi's core, but using tabstackengine instead of matrix allows for the spacing to be tightly controlled and tailored.

\documentclass{article}
\usepackage{tabstackengine}
\TABstackMath
\begin{document}
$\setstacktabbedgap{\Sstackgap} \def\grid{\tabbedShortstack{ \circ & \bullet & \circ \\ \bullet & \bullet & \bullet \\ \circ & \bullet & \circ }} \setstackgap{S}{7pt}\grid\qquad \setstackgap{S}{4pt}\grid\qquad \setstackgap{S}{1pt}\grid\qquad$
\end{document}