表格居中公式

Question

我无法正确可视化下表中的公式。

1) 行高太短。我想让第一行小于接下来的 4 行。我尝试了 arraystretch，但无法正确设置

2) 我无法将公式垂直居中。我尝试了 {|m{1in}|m{1in}|...} 命令，但结果很乱

3）我想将最后一行第一个单元格的文本向左对齐，但由于它位于多行上，我无法使 \multicolumn 正常工作

\begin{table*}[h]
\caption{Electromagnetic field regions.}
\label{tab:field_regions}
\centering
\resizebox{0.7\textwidth}{!}
{% 
    \begin{tabular} {|c|c|c|c|}

        %\toprule
        \hline
        \rowcolor[gray]{0.85}

      \textbf{Ratio $D_a/\lambda$}              & \textbf{Near field}        & \textbf{Mid field}        & \textbf{Far field} \\ 

      \hline

     $\displaystyle \frac{D_a}{\lambda}<1$          & $\displaystyle \frac{d}{\lambda}<1$      & -                         & $\displaystyle\frac{d}{\lambda}>1$ \\ 

     \hline

       $\rule{0pt}{20pt} \displaystyle 1<\frac{D_a}{\lambda}<10 $              & $\displaystyle \frac{d}{\lambda}<1.2\frac{D_a}{\lambda}$  & $\displaystyle 1.2 \frac{D_a}{\lambda}<\frac{d}{\lambda}<2\left(\frac{D_a}{\lambda}\right)^2$ & $\displaystyle \frac{d}{\lambda}>2\left(\frac{D_a}{\lambda}\right)^2 $ \\

       \hline

      $\displaystyle \frac{D_a}{\lambda}>10$ & $\displaystyle \frac{d}{\lambda}<\frac{1}{2} \sqrt[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{\lambda}\right)^4} & \displaystyle \frac{1}{2}\sqrt[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{\lambda}\right)^4}<\frac{d}{\lambda}< 2\left(\frac{D_a}{\lambda}\right)^2 $ &  $\displaystyle\frac{d}{\lambda}>2\left(\frac{D_a}{\lambda}\right)$\\ 

        \hline

      \cellcolor[gray]{0.85}  \makecell{\textbf{Dominant term} \\ \textbf{in the region}} & $\displaystyle  \frac{1}{d^3} $ & $\displaystyle \frac{1}{d^2}$ & $\displaystyle \frac{1}{d}$ \\           
      \hline          
    \end{tabular}}\end{table*}

Answer 1

\documentclass{article}
\usepackage{amsmath,graphicx,colortbl,makecell}
\begin{document}

\newcommand{\addstrut}[1]{\vcenter{\hbox{\rule{0pt}{#1}}}}

\begin{table*}[!htb]
\caption{Electromagnetic field regions.}
\label{tab:field_regions}
\centering
\resizebox{0.7\textwidth}{!}
{% 
    \begin{tabular}{|*4{>{$\displaystyle}c<{$}|}}
      %\toprule
      \hline
      \rowcolor[gray]{0.85}
      \textbf{Ratio $D_a/\lambda$} & \textbf{Near field}   & \textbf{Mid field} & \textbf{Far field} \\
      \hline
      \frac{D_a}{\lambda}<1      &  \frac{d}{\lambda}<1    & -               & \frac{d}{\lambda}>1 \addstrut{3em}\\ 
     \hline
       \rule{0pt}{20pt} \displaystyle 1<\frac{D_a}{\lambda}<10               &  \frac{d}{\lambda}<1.2\frac{D_a}{\lambda}  &  1.2 \frac{D_a}{\lambda}<\frac{d}{\lambda}<2\left(\frac{D_a}{\lambda}\right)^2 &  \frac{d}{\lambda}>2\left(\frac{D_a}{\lambda}\right)^2  \addstrut{3em}\\
       \hline
       \frac{D_a}{\lambda}>10 &  \frac{d}{\lambda}<\frac{1}{2} \sqrt[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{\lambda}\right)^4} &  \frac{1}{2}\sqrt[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{\lambda}\right)^4}<\frac{d}{\lambda}< 2\left(\frac{D_a}{\lambda}\right)^2  &  \frac{d}{\lambda}>2\left(\frac{D_a}{\lambda}\right) \addstrut{3.5em}\\ 
        \hline
      \cellcolor[gray]{0.85}\makecell[l]{\textbf{Dominant term}\\\textbf{in the region}} &   \frac{1}{d^3}  &  \frac{1}{d^2} &  \frac{1}{d} \addstrut{3em}\\           
      \hline          
    \end{tabular}
}
\end{table*}

\end{document}

Answer 2

我建议使用该包简化一些代码cellspace，并改进布局（特别是在caption 上面的标题和表格之间提供更合理的垂直间距）：

\documentclass[twocolumn]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{siunitx, caption, adjustbox, makecell, array, cellspace}
\setlength{\cellspacetoplimit}{6pt}
\setlength{\cellspacebottomlimit}{6pt}
\usepackage[table]{xcolor}

\begin{document}

\begin{table*}[h]
\caption{Electromagnetic field regions.}
\label{tab:field_regions}
\centering
\resizebox{0.7\textwidth}{!}
{\everymath{\displaystyle}%
    \begin{tabular} {|*{4}{Cc|}}
        \hline
        \rowcolor[gray]{0.85}
      \textbf{Ratio \boldmath$D_a/\lambda$} & \textbf{Near field} & \textbf{Mid field} & \textbf{Far field} \\
      \hline
     $\frac{D_a}{λ} < 1$ & $ \frac{d}{λ} < 1$ & $-$ & $\frac{d}{λ} > 1$ \\
     \hline
       $\rule{0pt}{20pt} 1 < \frac{D_a}{λ} < 10 $ & $ \frac{d}{λ} < 1.2\,\frac{D_a}{λ}$ & $ 1.2\, \frac{D_a}{λ} < \frac{d}{λ} < 2\left(\frac{D_a}{λ}\right)^{\mkern-5mu 2}$ & $ \frac{d}{λ} > 2\left(\frac{D_a}{λ}\right)^{\mkern-5mu 2} $ \\
       \hline
 $ \frac{D_a}{λ} > 10$ & $ \frac{d}{λ} < \frac{1}{2} √[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{λ}\right)^{\mkern-5mu 4}}$ & $ \frac{1}{2}√[\leftroot{-1}\uproot{2}\scriptstyle 3]{\left(\frac{D_a}{λ}\right)^{\mkern-5mu 4}} < \frac{d}{λ} < 2\left(\frac{D_a}{λ}\right)^{\mkern-5mu 2} $ & $\frac{d}{λ} > 2\left(\frac{D_a}{λ}\right)$\\
 \hline
 \cellcolor[gray]{0.85} \makecell{\textbf{Dominant term} \\ \textbf{in the region}} & $ \frac{1}{d³} $ & $ \frac{1}{d²}$ & $ \frac{1}{d}$ \\
 \hline
    \end{tabular}}\end{table*}

    \end{document}