我有一张满是相量的表，我试图将其写如下：
\documentclass[a4paper,journal]{article}
\usepackage[cmex10]{amsmath}
\begin{document}
\begin{table}[h!]
\caption{Bus Voltages}
\label{tab:appdx-busvoltages}
\begin{center}
\begin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}
\hline
\hline
\textbf{Bus} & \multicolumn{2}{c}{\textbf{$V$ (p.u.)}} \\
\hline
b1 & 1.0 & 0.00 & * \\
b2 & 0.8983 & -7.12& \\
b3 & 0.9136 & -5.80 &\\
b4 & 0.8841 & -9.01 &\\
\hline
\hline
\end{tabular}
\end{center}
* \textbf{b1} is the `slack bus', and has such has a fixed voltage.
\end{table}
\end{document}
它可以工作，因为它会产生以下输出：
但我也收到一堆错误：
paper1.tex:111: Illegal parameter number in definition of \reserved@a. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@fortmp. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@nextchar. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Illegal parameter number in definition of \@preamble. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:111: Only one # is allowed per tab. [...gin{tabular}{c|r@{$\angle$}r@{$^\circ$}l}]
paper1.tex:117: Missing # inserted in alignment preamble. [ b1 & 1.0 &]
paper1.tex:117: Missing $ inserted. [ b1 & 1.0 &]
paper1.tex:117: Missing $ inserted. [ b1 & 1.0 &]
paper1.tex:117: Missing $ inserted. [ b1 & 1.0 &]
paper1.tex:117: Missing $ inserted. [ b1 & 1.0 &]
paper1.tex:118: Missing # inserted in alignment preamble. [ b2 & 0.8983 &]
paper1.tex:118: Missing $ inserted. [ b2 & 0.8983 &]
paper1.tex:118: Missing $ inserted. [ b2 & 0.8983 &]
paper1.tex:118: Missing $ inserted. [ b2 & 0.8983 &]
paper1.tex:118: Missing $ inserted. [ b2 & 0.8983 &]
paper1.tex:119: Missing # inserted in alignment preamble. [ b3 & 0.9136 &]
paper1.tex:119: Missing $ inserted. [ b3 & 0.9136 &]
paper1.tex:119: Missing $ inserted. [ b3 & 0.9136 &]
paper1.tex:119: Missing $ inserted. [ b3 & 0.9136 &]
paper1.tex:119: Missing $ inserted. [ b3 & 0.9136 &]
paper1.tex:120: Missing # inserted in alignment preamble. [ b4 & 0.8841 &]
paper1.tex:120: Missing $ inserted. [ b4 & 0.8841 &]
paper1.tex:120: Missing $ inserted. [ b4 & 0.8841 &]
paper1.tex:120: Missing $ inserted. [ b4 & 0.8841 &]
paper1.tex:120: Missing $ inserted. [ b4 & 0.8841 &]
@{$\angle$}如果我从列定义中删除\begin{tabular}{...，错误就会消失。知道为什么会发生这种情况吗/我如何才能实现相同的格式而不会引发这些错误？
答案1
如果我加载array包裹。
\documentclass{article}
\usepackage{array}
\begin{document}
\begin{table}[h!]
\caption{Bus Voltages}
\label{tab:appdx-busvoltages}
\centering
\begin{tabular}{c|r@{$\angle$}l@{$^\circ$}l}
\hline
\hline
\textbf{Bus} & \multicolumn{3}{c}{\textbf{$V$ (p.u.)}} \\
\hline
b1 & 1.0 & & * \\
b2 & 0.8983 && \\
b3 & 0.9136 & &\\
b4 & & &\\
\hline
\hline
\end{tabular}
* \textbf{b1} is the `slack bus', and has such has a fixed voltage.
\end{table}
\end{document}