Merging cells in LaTeX tables

Question

Hi there,

I have a very simple table:

\begin{table}[t]
\begin{tabular}{|c||c|c|c|}
\hline
\multirow{2}{*}{Implementation}         & Test 1  & Test2  &  Test3    \\\hline
                                        & \multicolumn{3}{|c|}{results}   \\\hline\hline
\end{tabular}
\end{table}

It works almost "perfect", the only problem that I have is that the hline still goes through the first two cells that I have merged. Basically, it looks like this

"-------------------------------------------------"
"|                | Test 1 | Test 2 | Test 3 |"
" ----Implementation-------------------------------"
"|                |     results      |"  
"-------------------------------------------------"

However, it should like this:

"-------------------------------------------------" 
"|               | Test 1 | Test 2 | Test 3 |"
"   Implementation    ---------------------------"
"|               |      results     |"   
"-------------------------------------------------"

Anyone an idea how to get rid of the line in the first column?

Thanks

Answer 1

The command you want is \cline{i-j} which lets you draw a row divider across only certain columns. See http://www.giss.nasa.gov/tools/latex/ltx-214.html for details.

In particular, you'll want to use \cline{2-4} to draw a horizontal line across just the columns you mentioned. Here's your code with the one change:

\begin{table}[t]
\begin{tabular}{|c||c|c|c|}
\hline
\multirow{2}{*}{Implementation}         & Test 1  & Test2  &  Test3    \\\cline{2-4}
                                        & \multicolumn{3}{|c|}{results}   \\\hline\hline
\end{tabular}
\end{table}

Answer 2

Well, to not address your question, I'll note that many authorities suggest minimizing the amount of internal ink in your table (i.e. ditch the \hlines between ordinary rows), and using something line the last figure here.

If you are not constrained by some tightly defined style guide, this would be my solution.