Creating table with sub-elements [closed]

Question

I want to build a table like this:

I have tried a code but it doesn't work properly:

\begin{table}[htp]
\caption{The temporal outlier detection accuracy of hourly mean values with respect to the MFs in 2007-09-30}
    \label{tab:todh30}
            \centering
                \footnotesize\setlength{\tabcolsep}{2.5pt}
\begin{tabular}{|c|c|c|c|c|c|c|c|c|}
\hline
Node ID   & \multicolumn{2}{c|}{Density-based} \\ \cline{2-3} & \multicolumn{2}{c|}{Mahalanobis distance-based} \\ \cline{2-3} & \multicolumn{2}{c|}{Running average-based} \\ \cline{2-3}
    & DR\%  &  FPR\% \\  \hline & DR\%  &  FPR\% \\ \hline  & DR\%  &  FPR\% \\ \hline
25   & 100    & 71      \\  \hline  & 100    & 71      \\  \hline  & 100    & 60      \\ \hline
28 & 100    & 57     \\ \hline   & 100    & 57      \\ \hline  & 66    & 60      \\ \hline
29   & 100    & 62      \\ \hline   & 100    & 57      \\  \hline  & 100    & 50      \\ \hline
31   & 100    & 57      \\  \hline & 50    & 66      \\ \hline   & 66   & 60      \\ \hline
32   & 100    & 71      \\  \hline  & 100    & 66      \\  \hline & 100    & 66      \\ \hline
    \end{tabular}
\end{table}

Answer 1

I made a small example which shows the basic commands that you'll need.

Explanations

• tabular is the standard environment for tables in LaTeX that does not require extra packages
• the second argument is number and also the type of columns, in this case |c|c|c|, which means that we have 3 centered lines seperated by a vertical line (|).
• \hline inserts a line over the whole table width
• \cline inserts a line under a range of given columns, here \cline{2-3}, so we have a line under all colums from 2 to 3 (2 and 3 included)
• probably the most important: \multicolumn{2}{c|}{some text}:
  • the first argument gives the number of columns over which the cell will stretch
  • the second argument specifies the type of column (as before), in case your wondering why you need c| just try it without | then it should be clear
  • the last argument is the text you wish to have in this particular cell
• IMPORTANT with \\ you end the line and enter a new line, so don't use it if you still want to add colums, instead of rows

Code

\documentclass{article}

\begin{document}

\begin{tabular}{|c|c|c|}
\hline
n   & \multicolumn{2}{c|}{Running average-based} \\ \cline{2-3}
    & DR\%  &  FPR\% \\ \hline
6   & 19    & 1      \\ \hline
TOD & 72    & 11     \\ \hline
\end{tabular}

\end{document}

Result

Here also a improved version of your code.

\documentclass{article}

\begin{document}

\begin{table}[htp]
\caption{The temporal outlier detection accuracy of hourly mean values with respect to the MFs in 2007-09-30}
\label{tab:todh30}
\centering
\footnotesize\setlength{\tabcolsep}{2.5pt}
\begin{tabular}{|c|c|c|c|c|c|c|c|c|}
\hline
Node ID   & \multicolumn{2}{c|}{Density-based}  & \multicolumn{2}{c|}{Mahalanobis distance-based}  & \multicolumn{2}{c|}{Running average-based} \\ \cline{2-7}

   & DR\%   &  FPR\%  & DR\%   &  FPR\%  & DR\%   &  FPR\%  \\ \hline
25 & 100    & 71      & 100    & 71      & 100    & 60      \\ \hline
28 & 100    & 57      & 100    & 57      & 66     & 60      \\ \hline
29 & 100    & 62      & 100    & 57      & 100    & 50      \\ \hline
31 & 100    & 57      & 50     & 66      & 66     & 60      \\ \hline
32 & 100    & 71      & 100    & 66      & 100    & 66      \\ \hline
\end{tabular}
\end{table}

\end{document}

Resulting in

Answer 2

This can be a good starting point and you can modify it based on your needs:

\documentclass{article}

\begin{document}
    \begin{tabular}{|l||l|l||l|l|}
    \hline
     &\multicolumn{2}{l|}{A}&\multicolumn{2}{l|}{B}\\
    \cline{2-5}
     n&A1&\textbf{A2}&B1&\textbf{B2}\\
    \hline\hline
    0&3&\textbf{7}&11&\textbf{15}\\
    1&4&\textbf{8}&12&\textbf{16}\\
    2&5&\textbf{9}&13&\textbf{17}\\
    3&6&\textbf{10}&14& \\
    \hline
    \end{tabular}
\end{document}

Credits to http://www.maths.tcd.ie for their template.