虽然有一些神秘的baseline微调...
\documentclass{article}
\usepackage{fourier}
\usepackage{amsmath}
\usepackage{nicematrix}
\usepackage{tikz}
\usepackage{lipsum}
\begin{document}
\lipsum[2]
\[
R_o =
\begin{bNiceArray}{ccc}[margin,last-row]
\begin{tikzpicture}
\clip (-.75,-.25) rectangle (1,3);
\draw
(-.45,0) -- ++(0,2.25)
(0.0,0) -- ++(0,2.25)
node[above] {$K$}
(+.45,0) -- ++(0,2.25);
\end{tikzpicture}
&
\begin{tikzpicture}[baseline=-1.25cm]
\draw
(0,0) rectangle (1.5,1.5)
(.75,1.5) node[above] {$K$}
(1.5,.75) node[right] {$K$}
;
\end{tikzpicture}
&
\begin{tikzpicture}[baseline=-2cm]
\draw
(0,-.5) -- ++(2,0)
(0,0) -- ++(2,0) node[right] {$K$}
(0,.5) -- node[midway,above] {$M$} ++(2,0);
\end{tikzpicture} \\
\mathbf{S}
&
% \mathbb{E}(\mathbf{a}\mathbf{a}^H)
\tikz[baseline=5.5ex]{
\node (O) {non-singular};
\node at (0,1) {$\mathbb{E}(\mathbf{a}\mathbf{a}^H) $}edge[latex-] (O.north);
}
&
\mathbf{S}^H
\end{bNiceArray}
\]
\lipsum[2]
\end{document}






























问 绘制如下形式的「抽象」矩阵的最佳实践?