我正在使用此代码来对齐方程的方程单位并创建漂亮的方程图例。
最小工作示例：
\documentclass{article}
\usepackage{amsmath}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{siunitx}
%--------------------------------------------------------------------------------------------
% ---- The following part is to align the units of right the equations: ---------------------
%--------------------------------------------------------------------------------------------
\makeatletter%
\providecommand\add@text{}%
\newcommand\addunit[1]{%
\gdef\add@text{[\si{#1}]\gdef\add@text{}}}%
\renewcommand\tagform@[1]{%
\maketag@@@{\llap{\add@text\qquad}(\ignorespaces#1\unskip\@@italiccorr)}%
}%
\makeatother%
%--------------------------------------------------------------------------------------------
% ---- The following part is for equation legends including symbol, description and unit ----
%--------------------------------------------------------------------------------------------
\newenvironment{legend*}{%
\par\vspace{\abovedisplayskip}\noindent%
\begingroup%
\leftskip = 3em% Indent from left, alternative 4em
\noindent\text{\hspace{0.2em} where}%
\par\vspace{\abovedisplayskip}\noindent%
\tabularx{\columnwidth}{>{\(}l<{\)} @{\hspace{2em}} l @{\hspace{2em}} >{\raggedright\arraybackslash}>{[} c<{]}}}%
{\endtabularx\par\vspace{2em}%
\par%
\endgroup%
}%
%--------------------------------------------------------------------------------------------
% ---- Document part ------------------------------------------------------------------------
%--------------------------------------------------------------------------------------------
\begin{document}
\begin{equation}
V = BC \addunit{\square\meter}
\end{equation}
\begin{legend*}
V & Filter volume & \si{\cubic\meter}\\
B & Density of the filter & \si{\kilo\gram\per\cubic\meter}\\
C & Filter mass & \si{\kilo\gram}\\
\end{legend*}
\end{document}
结果截图：
问题说明：
如您所见，这看起来不错，但并不完美。因此，我想将图例的单位与公式的单位对齐，使其在同一行上。
所需状态的屏幕截图：
我该如何修改此代码？
答案1
使用X列：
\documentclass{article}
\usepackage{amsmath}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{siunitx}
%--------------------------------------------------------------------------------------------
% ---- The following part is to align the units of right the equations: ---------------------
%--------------------------------------------------------------------------------------------
\makeatletter
\providecommand\add@text{}
\newcommand\addunit[1]{%
\gdef\add@text{(\si{#1})\gdef\add@text{}}
}
\renewcommand\tagform@[1]{%
\maketag@@@{\llap{\add@text\qquad}(\ignorespaces#1\unskip\@@italiccorr)}%
}
\makeatother
%--------------------------------------------------------------------------------------------
% ---- The following part is for equation legends including symbol, description and unit ----
%--------------------------------------------------------------------------------------------
\newenvironment{legend*}{%
\par\vspace{\abovedisplayskip}\noindent
\begingroup
\tabularx{\columnwidth}{
@{\hspace{3em}}
>{\(}l<{\)}
@{\hspace{2em}}
l
@{\hspace{2em}}
>{\raggedright\arraybackslash}>{\hfill(} X<{)\qquad\hphantom{\theequation}}
@{}
}\multicolumn{3}{@{\hspace{3em}}l@{}}{where}\\[1ex]
}%
{\endtabularx\par\vspace{2em}%
\par
\endgroup
}%
%--------------------------------------------------------------------------------------------
% ---- Document part ------------------------------------------------------------------------
%--------------------------------------------------------------------------------------------
\begin{document}
\begin{equation}
V = BC \addunit{\square\meter}
\end{equation}
\begin{legend*}
V & Filter volume & \si{\cubic\meter}\\
B & Density of the filter & \si{\kilo\gram\per\cubic\meter}\\
C & Filter mass & \si{\kilo\gram}\\
\end{legend*}
\end{document}
