有没有办法对齐增强矩阵中的垂直线（使它们位于对齐方程的下方）？当矩阵中的符号发生变化时，它会变得扭曲，我正在寻找一种更好的视觉表示。
\begin{align*}
\rightsquigarrow
&\left( \begin{array}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
2 & 1 & 2 & 0 & 1 & 0\\
2 & 4 & 2 & 0 & 0 & 2\\
\end{array}\right)
\rightsquigarrow\\
\text{II} - \text{I}, \text{III}-\text{I}\rightsquigarrow
&\left( \begin{array}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
0 & -3 & -1 & -1 & 1 & 0\\
0 & 0 & -1 & -1 & 0 & 2\\
\end{array}\right)
\rightsquigarrow
\end{align*}
答案1
该包提供了一个带有键的nicematrix环境。在该环境中，所有环境（、、等）的所有列都将具有相同的宽度。您需要多次编译。{NiceMatrixBlock}auto-columns-widthnicematrix{NiceMatrix}{NiceArray}{NiceTabular}
\documentclass{article}
\usepackage{nicematrix}
\usepackage{amssymb}
\begin{document}
\begin{NiceMatrixBlock}[auto-columns-width]
\begin{align*}
\rightsquigarrow
&\begin{pNiceArray}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
2 & 1 & 2 & 0 & 1 & 0\\
2 & 4 & 2 & 0 & 0 & 2\\
\end{pNiceArray}
\rightsquigarrow\\
\text{II} - \text{I}, \text{III}-\text{I}\rightsquigarrow
&\begin{pNiceArray}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
0 & -3 & -1 & -1 & 1 & 0\\
0 & 0 & -1 & -1 & 0 & 2\\
\end{pNiceArray}
\rightsquigarrow
\end{align*}
\end{NiceMatrixBlock}
\end{document}
答案2
根据您是否希望列也对齐，我建议两种方法：
第一种方式：
第二种方式：
第一个输出的代码：
\documentclass{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\begin{document}
\begin{alignat*}{3}
& \rightsquigarrow
& \left( \begin{array}{rrr}
2 & 4 & 3 \\
2 & 1 & 2 \\
2 & 4 & 2 \\
\end{array} \right|
&
\left. \begin{array}{@{}rrr}
1 & 0 & 0 \\
0 & 1 & 0 \\
0 & 0 & 2 \\
\end{array} \right)
&& \rightsquigarrow\\
\text{II} - \text{I}, \text{III}-\text{I}
& \rightsquigarrow
& \; % add a little space after the arrow
\left( \begin{array}{rrr}
2 & 4 & 3 \\
0 & -3 & -1 \\
0 & 0 & -1 \\
\end{array}\right|
&
\left. \begin{array}{@{}rrr}
1 & 0 & 0 \\
-1 & 1 & 0 \\
-1 & 0 & 2 \\
\end{array} \right)
&&\rightsquigarrow
\end{alignat*}
\end{document}
第二个输出的代码：
\documentclass{article}
\usepackage{array}
\usepackage{amsmath}
\usepackage{amsfonts}
% Let's have fun and spare one skip register.
\makeatletter
\newcommand*{\@@mydefineColType}[2]{%
\newcolumntype{#2}{>{$}W{r}{#1}<{$}}%
}
\newcommand*{\@mydefineColType}[2]{%
\expandafter\@@mydefineColType\expandafter{\the#1}{#2}%
}
\newcommand*{\mydefineColType}[2]{%
\expandafter\@mydefineColType\my@exchange{#1}{#2}%
}
\newcommand{\my@exchange}[2]{{#2}{#1}}
\makeatother
\begin{document}
\newlength{\mylength}%
\settowidth{\mylength}{$-3$}%
% For columns containing at least one negative number
\mydefineColType{N}{\mylength}% stores the current value of \mylength
\settowidth{\mylength}{$3$}%
% For columns containing no negative number
\mydefineColType{P}{\mylength}% stores the current value of \mylength
\begin{alignat*}{3}
& \rightsquigarrow \; % add a little space after the arrow
& \left( \begin{array}{PNN}
2 & 4 & 3 \\
2 & 1 & 2 \\
2 & 4 & 2 \\
\end{array} \right|
&
\left. \begin{array}{@{}NPP}
1 & 0 & 0 \\
0 & 1 & 0 \\
0 & 0 & 2 \\
\end{array} \right)
&& \rightsquigarrow\\
\text{II} - \text{I}, \text{III}-\text{I}
& \rightsquigarrow \; % add a little space after the arrow
& \left( \begin{array}{PNN}
2 & 4 & 3 \\
0 & -3 & -1 \\
0 & 0 & -1 \\
\end{array}\right|
&
\left. \begin{array}{@{}NPP}
1 & 0 & 0 \\
-1 & 1 & 0 \\
-1 & 0 & 2 \\
\end{array} \right)
&&\rightsquigarrow
\end{alignat*}
\end{document}
答案3
\MoveEqLeft使用来自 的命令的可能性mathtools。通过反复试验找到了可选参数的值：
\documentclass{article}
\usepackage{mathtools}
\usepackage{amssymb}
\begin{document}
\begin{align*}
\rightsquigarrow
\MoveEqLeft[-1.55]\left( \begin{array}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
2 & 1 & 2 & 0 & 1 & 0\\
2 & 4 & 2 & 0 & 0 & 2\\
\end{array}\right)
\rightsquigarrow\\
\text{II} - \text{I}, \text{III}-\text{I}\rightsquigarrow
&\left( \begin{array}{rrr|rrr}
2 & 4 & 3 & 1 & 0 & 0\\
0 & -3 & -1 & -1 & 1 & 0\\
0 & 0 & -1 & -1 & 0 & 2\\
\end{array}\right)
\rightsquigarrow
\end{align*}
\end{document}
