我怎样才能将带有编号的方程式放入表格中？

Question

我想要将多个方程式放入如下表所示的表格中。

解为 x	求解 y
x=a+b（1.1）	y=d+e（1.2）
x = d + b * k (1.3)	y=j^2（1.4）

方程式应左对齐，编号应右对齐。我无法将方程式环境放入表格中，因此方程式将被编号。

Answer 1

更新
正如评论中指出的那样，第一个版本没有添加引用方程的选项。因此，\addtag被重新设计并直接移到单元格内，使编号成为可选项。此外，参数\addtag[<label>]是可选的。它是一个标签名称，仅在需要引用方程时才是必需的。

新代码

\documentclass{article}
\usepackage{array}
\usepackage{etoolbox}
\newcommand\addtag[1][]{%
  \refstepcounter{equation}\hfill(\theequation)%
  \notblank{#1}{\label{#1}}{}}
\counterwithin[\arabic]{equation}{section}


\begin{document}
\section{First section}
\begin{table}[tbh]
  \renewcommand*{\arraystretch}{1.5}
  \centering
  \caption{Equations}\label{tab:equations}
  \begin{tabular}{| *2{>{\(}p{5cm}<{\)}|}}
    \hline
    \textbf{Solved for $x$} & \textbf{Solved for $y$} \\
    \hline
    x = a + b          \addtag[a] & y = d + e \addtag[b] \\ 
    x = d + b \times k            & y = j^2   \addtag[c] \\ 
    \hline
  \end{tabular}
\end{table}

References: Euqation~\ref{a}, Equation~\ref{b}, and Equation~\ref{c}.
\end{document}

编辑。
注意方程式编号。文档类article将方程式定义为单个数字，而report和book将添加章节以形成组合标签，即(2.1)只要\chapter使用即可。如果您希望仅使用即可获得相同的效果article，请将以下代码添加到序言中：

 \counterwithin[\arabic]{equation}{section}

EDIT2.（显示样式）
默认情况下，内联方程式使用文本样式排版，这是一种更紧凑的形式，适合文本之间的表达式。这可以通过附加\displaystyle到每个表达式来更改。但是，>{...}可以自动对列中的每个单元格执行此操作。请参阅下面的代码片段。您只需\displaystyle在后面添加\(

  \begin{tabular}{| *2{>{\(\displaystyle}p{5cm}<{\)}|}}
    % ...
  \end{tabular}

更改后，方程式可能不再适合行。在这种情况下，将拉伸因子增加到\arraystretch大于 1.8 的值，例如

\renewcommand*{\arraystretch}{1.85}

---

这是一个简单的解决方案

\documentclass[12pt]{article}
\usepackage{array}
\newcommand\addtag{\;\refstepcounter{equation}(\theequation)}
\begin{document}
\begin{table}[tbh]
  \renewcommand*{\arraystretch}{1.5}
  \centering
  \caption{Equations}\label{tab:equations}
  \begin{tabular}{| *2{>{\(}p{5cm}<{\hfill\addtag\)}|}}
    \hline
    \multicolumn{1}{|l|}{\textbf{Solved for $x$}}
    & \multicolumn{1}{l|}{\textbf{Solved for $y$}} \\
    \hline
    x = a + b          & y = d + e \\
    x = d + b \times k & y = j^2 \\
    \hline
  \end{tabular}
\end{table}
\end{document}

Answer 2

正如 @Rmano 在评论中建议的那样，可以使用Heiko 的回答在这里。要使列正确对齐，您只需使用具有定义宽度的列，而\hfill不仅仅是不可中断的空间~。这里有一个建议，代码略有改进：

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx}
\makeatletter
\NewDocumentCommand{\InlineEquation}{om}{%
  \begingroup
    % Put \refstepcounter at the beginning, because
    % package `hyperref' sets the anchor here.
    \refstepcounter{equation}%
    % prevent line breaks inside equation
    \relpenalty=10000 %
    \binoppenalty=10000 %
    \ensuremath{%
      % \displaystyle % larger fractions, ...
      \IfNoValueF{#1}{\label{#1}}% add label if optional argument is used
      #2%
    }%
    \hfill\@eqnnum
  \endgroup
}
\makeatother

\begin{document}
\noindent\begin{tabularx}{\textwidth}{|X|X|}
  \hline
  \textbf{solved for $x$} & \textbf{solved for $y$}\\
  \hline
  \InlineEquation[eq:first]{x = a + b} & \InlineEquation[eq:second]{y =d + e}\\
  \InlineEquation[eq:third]{x = d + b \times k} & \InlineEquation{y = j^{2}} \\
  \hline
\end{tabularx}

See \eqref{eq:first}, \eqref{eq:second}, \eqref{eq:third} and the one without
label.
\end{document}

顺便说一句：我建议不要使用垂直线和大量水平线。查看包装booktabs了解有关如何制作漂亮表格的信息。

如果方程编号也取决于表格编号，则可以使用：

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx}
\usepackage{booktabs}
\usepackage{caption}% To have captions formatting to be used above table instead of below.
\newcounter{outsideequation}
\makeatletter
\NewDocumentCommand{\TableEquation}{om}{%
  \begingroup
    % Put \refstepcounter at the beginning, because
    % package `hyperref' sets the anchor here.
    \refstepcounter{equation}%
    % prevent line breaks inside equation
    \relpenalty=10000 %
    \binoppenalty=10000 %
    \ensuremath{%
      % \displaystyle % larger fractions, ...
      \IfNoValueF{#1}{\label{#1}}% add label if optional argument is used
      #2%
    }%
    \hfill\@eqnnum
    \endgroup
}
\newenvironment{UseTableEquations}{%
  \setcounter{outsideequation}{\value{equation}}%
  \setcounter{equation}{0}%
  \counterwithin{equation}{table}%
}{%
  \setcounter{equation}{\value{outsideequation}}%
  \counterwithout{equation}{table}%
}
\makeatother
\begin{document}
\begin{table}
  \renewcommand*{\arraystretch}{1.2}
  \caption{Table with equations}
  \begin{UseTableEquations}
    \begin{tabularx}{\textwidth}{XX}
      \toprule
      \textbf{solved for $x$} & \textbf{solved for $y$}\\
      \midrule
      \TableEquation[eq:first]{x = a + b} & \TableEquation[eq:second]{y =d +
        e}\\
      \addlinespace
      \TableEquation[eq:third]{x = d + b \times k} & \TableEquation{y = j^{2}} \\
      \bottomrule
    \end{tabularx}
    \end{UseTableEquations}
\end{table}

See \eqref{eq:first}, \eqref{eq:second}, \eqref{eq:third} and the one without
label.

\end{document}

或者在表格下方添加表格标题：

\documentclass{article}
\usepackage{amsmath}
\usepackage{tabularx}
\usepackage{booktabs}
\newcounter{outsideequation}
\makeatletter
\NewDocumentCommand{\TableEquation}{om}{%
  \begingroup
    \advance\c@table by 1\relax% because table counter is 1 to low
    % before \caption
    % Put \refstepcounter at the beginning, because
    % package `hyperref' sets the anchor here.
    \refstepcounter{equation}%
    % prevent line breaks inside equation
    \relpenalty=10000 %
    \binoppenalty=10000 %
    \ensuremath{%
      % \displaystyle % larger fractions, ...
      \IfNoValueF{#1}{\label{#1}}% add label if optional argument is used
      #2%
    }%
    \hfill\@eqnnum
    \endgroup
}
\newenvironment{UseTableEquations}{%
  \setcounter{outsideequation}{\value{equation}}%
  \setcounter{equation}{0}%
  \counterwithin{equation}{table}%
}{%
  \setcounter{equation}{\value{outsideequation}}%
  \counterwithout{equation}{table}%
}
\makeatother
\begin{document}
\begin{table}
  \renewcommand*{\arraystretch}{1.2}
  \begin{UseTableEquations}
    \begin{tabularx}{\textwidth}{XX}
      \toprule
      \textbf{solved for $x$} & \textbf{solved for $y$}\\
      \midrule
      \TableEquation[eq:first]{x = a + b} & \TableEquation[eq:second]{y =d +
        e}\\
      \addlinespace
      \TableEquation[eq:third]{x = d + b \times k} & \TableEquation{y = j^{2}} \\
      \bottomrule
    \end{tabularx}
    \end{UseTableEquations}
  \caption{Table with equations}
\end{table}

See \eqref{eq:first}, \eqref{eq:second}, \eqref{eq:third} and the one without
label.

\end{document}