Vertical alignment of array inside tabular

Question

I would like to vertically align several table cells, one of which includes an array. Consider the following MWE:

\documentclass{article}

\usepackage{graphicx}
\usepackage{array}

\begin{document}

\begin{tabular}{*{5}{m{0.2\textwidth}}}
    Some text &
    \includegraphics[width=15mm]{example-grid-100x100pt} &
    \(\left(\begin{array}{cc}
        1 & 0 \\
        0 & 1
    \end{array}\right)\) &
    \((1,0,1,0)\) &
    \rule{15mm}{15mm}
\end{tabular}

\end{document}

Which yields (green reference line added by me):

The text, image, simple inline math, and rule are all correctly aligned vertically, but the array is pushed down. Instead I would have expected the following:

Why is the array not centered vertically? What is the easiest way to fix this?

Answer 1

Problem is in your \rule (where it has baseline?). If you encapsulate it in a some box, to which you can define baseline, for example with help of the macro \valign from the \adjustbox, the same do for image in the second column, than all elements of tabular in p columns type will have baseline vertical centered:

\documentclass{article}
\usepackage[export]{adjustbox} % also load graphicx package
\usepackage{array}

\begin{document}
\noindent%
\begin{tabular}{*{5}{>{\centering\arraybackslash}p{\dimexpr0.2\textwidth-2\tabcolsep}}} 
    Some text &
    \includegraphics[width=15mm,valign=c]{example-grid-100x100pt} &
    \(\left(\begin{array}{cc}
        1 & 0 \\
        0 & 1
    \end{array}\right)\) &  \((1,0,1,0)\) & \adjustbox{valign=c}{\rule{15mm}{15mm}}
    \end{tabular}
\end{document}

(red lines indicate text border)

As you can see, I also change columns width that table can fit in text area.