[Tex/LaTex] Center text over multicolumn in table

formattinghorizontal alignmentmulticolumntables

I have created a table that is the width of my page, but when trying to center the text in the top row over the merged cell, the text is not centering with respect to the entire length of the cell.

\documentclass[a4paper,twoside,12pt]{article}
\usepackage{graphicx}
\usepackage{array}
\newcolumntype{N}{>{\centering\arraybackslash}m{.5in}}
\newcolumntype{G}{>{\centering\arraybackslash}m{2in}}

\begin{document}

\begin{table}[H]
\centering
\begin{tabular}{N|N|N|N|N|N|N|N|N|}
\cline{2-9}
\multicolumn{1}{N|}{\textbf{}} & \multicolumn{4}{G|}{\textbf{Emissions (Pre Catalytic Converter)}} & \multicolumn{4}{G|}{\textbf{Emissions (Post Catalytic Converter)}} \\  \hline
\multicolumn{1}{|N|}{\textbf{Dyno Load (\%)}} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} \\ \hline
\multicolumn{1}{|N|}{10} & 0.77 & 23 & 523 & 14.0 & 0.09 & 18 & 130 & 13.8 \\ \hline
\multicolumn{1}{|c|}{30} & 0.78 & 13 & 555 & 14.2 & - & - & - & - \\ \hline
\multicolumn{1}{|c|}{70} & 0.70 & 14 & 580 & 14.4 & - & - & - & - \\ \hline
\multicolumn{1}{|c|}{90} & 0.74 & 15 & 630 & 14.5 & 0.70 & 15 & 618 & 14.6 \\ \hline
\multicolumn{1}{|c|}{Neutral} & 0.06 & 7 & 21 & 15.6 & 0.06 & 5 & 27 & 15.7 \\ \hline
\end{tabular}
\caption{\textbf{}}
\label{2000Emissions}
\end{table}

\end{document}

enter image description here

Best Answer

In this case it is easier to just use two lines for the titles:

enter image description here

Notes:

You don't need to use \multicolumn{1}{N|}{\textbf{}}, just leaving it blank is sufficient.

However, I think you table would lok much better if you eliminated the vertical rules and used the booktabs package:

enter image description here

Code:

\documentclass[a4paper,twoside,12pt]{article}
\usepackage{graphicx}
\usepackage{array}
\newcolumntype{N}{>{\centering\arraybackslash}m{.5in}}
\newcolumntype{G}{>{\centering\arraybackslash}m{2in}}

\newcommand*{\boldsymbol}[1]{#1}

\begin{document}

\begin{table}[H]
\centering
\begin{tabular}{N|N|N|N|N|N|N|N|N|}
\cline{2-9}
     & \multicolumn{4}{c|}{\textbf{Emissions (Pre}} & \multicolumn{4}{c|}{\textbf{Emissions (Post}} \\  
     & \multicolumn{4}{c|}{\textbf{Catalytic Converter)}} & \multicolumn{4}{c|}{\textbf{Catalytic Converter)}} \\  \hline
\multicolumn{1}{|N|}{\textbf{Dyno Load (\%)}} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} \\ \hline
\multicolumn{1}{|N|}{10} & 0.77 & 23 & 523 & 14.0 & 0.09 & 18 & 130 & 13.8 \\ \hline
\multicolumn{1}{|c|}{30} & 0.78 & 13 & 555 & 14.2 & - & - & - & - \\ \hline
\multicolumn{1}{|c|}{70} & 0.70 & 14 & 580 & 14.4 & - & - & - & - \\ \hline
\multicolumn{1}{|c|}{90} & 0.74 & 15 & 630 & 14.5 & 0.70 & 15 & 618 & 14.6 \\ \hline
\multicolumn{1}{|c|}{Neutral} & 0.06 & 7 & 21 & 15.6 & 0.06 & 5 & 27 & 15.7 \\ \hline
\end{tabular}
\caption{\textbf{}}
\label{2000Emissions}
\end{table}

\end{document}

Code: `booktabs`:

\documentclass[a4paper,twoside,12pt]{article}
\usepackage{graphicx}
\usepackage{array}
\usepackage{booktabs}
\newcolumntype{N}{>{\centering\arraybackslash}m{.5in}}
\newcolumntype{G}{>{\centering\arraybackslash}m{2in}}

\newcommand*{\boldsymbol}[1]{#1}

\begin{document}

\begin{table}[H]
\centering
\noindent
\begin{tabular}{N N N N N N N N N }\toprule
\multicolumn{1}{N }{\textbf{}} & \multicolumn{4}{c }{\textbf{Emissions (Pre}} & \multicolumn{4}{c }{\textbf{Emissions (Post}} \\  
\multicolumn{1}{c }{\textbf{}} & \multicolumn{4}{c }{\textbf{Catalytic Converter)}} & \multicolumn{4}{c }{\textbf{Catalytic Converter)}} \\ 
\cmidrule(lr){2-5}
\cmidrule(ll){6-9}
\multicolumn{1}{ N }{\textbf{Dyno Load (\%)}} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} & \textbf{CO (\%)} & \textbf{HC (ppm)} & \textbf{Nox (ppm)} & \textbf{$\boldsymbol{\mathrm{CO_2}}$ (\%)} \\ 
\cmidrule(lr){1-1}
\cmidrule(lr){2-5}
\cmidrule(ll){6-9}
\multicolumn{1}{ N }{10} & 0.77 & 23 & 523 & 14.0 & 0.09 & 18 & 130 & 13.8 \\ 
\multicolumn{1}{ c }{30} & 0.78 & 13 & 555 & 14.2 & - & - & - & - \\ 
\multicolumn{1}{ c }{70} & 0.70 & 14 & 580 & 14.4 & - & - & - & - \\ 
\multicolumn{1}{ c }{90} & 0.74 & 15 & 630 & 14.5 & 0.70 & 15 & 618 & 14.6 \\ 
\multicolumn{1}{ c }{Neutral} & 0.06 & 7 & 21 & 15.6 & 0.06 & 5 & 27 & 15.7 \\ 
\bottomrule
\end{tabular}
\caption{\textbf{}}
\label{2000Emissions}
\end{table}

\end{document}

Code:

\documentclass{article}
\usepackage{siunitx}
\usepackage{booktabs}

\begin{document}
\begin{table}[htp]
    \centering
    \begin{tabular}{lS[table-format=1.4]
                     S[table-format=1.4]
                     S[table-format=1.4]
                     S[table-format=1.4]}
        \toprule
            {\emph{Nodi}} & \multicolumn{4}{c}{PEP} \\
            \cmidrule(lr){2-5}
                        & \multicolumn{4}{c}{\num{10e-1}\quad\num{10e-3}}  \\
            \cmidrule(lr){2-5}
                        & {BC}   & {PNC}    & {BC} & {PNC} \\
        \midrule
        1               & 1.1107 & 1.1112  & 1.001  & 1.001 \\
        3               & 1.3046 & 1.1488  & 1.003  & 1.0029 \\
        7               & 1.597  & 1.1734  & 1.007  & 1.006 \\
        12              & 1.8435 & 1.188   & 1.0117 & 1.0089 \\
        20              & 2.0836 & 1.2009  & 1.0201 & 1.0122 \\
        25              & 2.1777 & 1.2064  & 1.0246 & 1.0134 \\
        35              & 2.3101 & 1.2141  & 1.0347 & 1.0153 \\
        50              & 2.4443 & 1.2223  & 1.0488 & 1.0167 \\
        65              & 2.5501 & 1.228   & 1.0636 & 1.0175 \\
        75              & 2.6109 & 1.2308  & 1.0723 & 1.0178 \\
        90              & 2.6915 & 1.235   & 1.0864 & 1.0184 \\
        100             & 2.7417 & 1.237   & 1.0954 & 1.0186 \\
        \bottomrule
    \end{tabular}
\end{table}
\end{document}

[Tex/LaTex] multicolumn table

I would like to suggest that you not use the multirow package. Instead, place all level-1 information in the first row of header.

I would also like to suggest that you use S[table-format=3.0] instead r for the second column. Columns 3 to 5 will look better if you use columns of type c. You may also want to replace the * multiplicative symbol with the more prominent \times symbol; you could write 1024$\times$1024, as is done in the code below, or you could write \num{1024x1024} (egreg's suggestion -- many thanks!), where \num is a macro provided by the siunitx package.. If you choose the latter input method, you may also want provide the instruction \sisetup{tight-spacing=true} in the preamble in order to avoid having a lot of whitespace around the \times symbols.

Separately, I think you should also consider getting rid of the whitespace to the left of the first column and to the right of the final column. The resulting look is shown in the second example below.

enter image description here

\documentclass{article}
\usepackage{booktabs,siunitx}
\begin{document}
\begin{table}
\centering
\begin{tabular}{ l S[table-format=3.0] c c c }
    \toprule
    Models & {Tris (M)} & Resolution &\multicolumn{2}{c}{Avg.\ FPS} \\
    \cmidrule(l){4-5}
    &&& moving & static \\
    \midrule
    Model 1 &   5 & 1024$\times$1024 & 40 & 60 \\
    Model 2 &  12 & 1024$\times$1024 & 40 & 60 \\
    Model 3 &  73 & 1024$\times$1024 & 40 & 40 \\
    Model 4 & 337 & 1024$\times$1024 & 20 & 30 \\
    \bottomrule
\end{tabular}

%% now, without whitespace to the left of first col and to the right of final col
\bigskip
\begin{tabular}{@{} l S[table-format=3.0] c c c @{}}
    \toprule
    Models & {Tris (M)} & Resolution &\multicolumn{2}{c}{Avg.\ FPS} \\
    \cmidrule(l){4-5}
    &&& moving & static \\
    \midrule
    Model 1 &   5 & 1024$\times$1024 & 40 & 60 \\
    Model 2 &  12 & 1024$\times$1024 & 40 & 60 \\
    Model 3 &  73 & 1024$\times$1024 & 40 & 40 \\
    Model 4 & 337 & 1024$\times$1024 & 20 & 30 \\
    \bottomrule
\end{tabular}
\end{table}
\end{document}

Best Answer

Notes:

Code:

Code: booktabs:

Related Solutions

[Tex/LaTex] Alignment at the center of two multicolumn

Code:

[Tex/LaTex] multicolumn table

Related Question

Code: `booktabs`: