[Tex/LaTex] Draw border for just one cell in a table

rulestables

How can I draw border for just one cell in a simple table?

\documentclass{article}
\usepackage{placeins}
\usepackage{booktabs ,float}
\begin{document}

\begin{table}[htbp]
    \centering
    \caption{Test Set }
    \begin{tabular}{cccc}
        \hline\hline

        \multicolumn{2}{c}{\textbf{Train}}&  \multicolumn{2}{c}{\textbf{Test}}\\
        \cmidrule(r){1-2} \cmidrule(r){3-4} 
        \textbf{A}  & \textbf{\# D} & \textbf{\# E} & \textbf{\# E} \\
        \hline
        B & 9.6 & 62.8& 62.8 \\
        C & 12.0 & 78.9 & 62.8 \\
        C & 12.0 & 78.9 & 62.8 \\           
        \hline
    \end{tabular}       
\end{table} 
\end{document}

Best Answer

\documentclass{article}
\usepackage{placeins}
\usepackage{booktabs ,float}

\begin{document}
\begin{table}[htbp]
    \centering
\renewcommand\arraystretch{1.2}
    \caption{Test Set }
    \begin{tabular}{cccc}
        \hline\hline

        \multicolumn{2}{c}{\textbf{Train}}&  \multicolumn{2}{c}{\textbf{Test}}\\
        \cmidrule(r){1-2} \cmidrule(r){3-4}
        \textbf{A}  & \textbf{\# D} & \textbf{\# E} & \textbf{\# E} \\
        \hline
        B & 9.6 & 62.8& 62.8 \\
        C & 12.0 & \fbox{78.9} & 62.8 \\
        C & 12.0 & 78.9 & 62.8 \\
        \hline
    \end{tabular}
\end{table}
\end{document}

i would use rules from booktabs for all horizontal rules in table not just one ...

Related Question