Fixed table width with even alignment

Question

I like to use a table layout where the width of the table is fixed to 7cm. I can do this using:

\documentclass{book}
\usepackage{array,tabularx}
\newcolumntype{+}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{^}{>{\currentrowstyle}}
\newcommand{\rowstyle}[1]{\gdef\currentrowstyle{#1}%
  #1\ignorespaces}

\makeatletter
\g@addto@macro\@floatboxreset{\centering\sffamily\small}
\makeatother


\begin{document}

\begin{table}

\begin{tabular*}{7cm}{@{\extracolsep{\fill}}|>{\bfseries}+l|^c|^c|}
\hline\rowstyle{\bfseries}%
            & property  & number    \\ \hline
Something   & yes       & 1554      \\
Item        & no        & 2         \\ \hline
\end{tabular*}\\
\vspace{.5cm}

\newcolumntype{;}{l@{}}% dummy column
\begin{tabular*}{7cm}{@{\extracolsep{\fill}}|;>{\bfseries}+l;|^c;|^c;|}
\hline\rowstyle{\bfseries}%
&            && property  && number  &  \\ \hline
&Something   && yes       && 1554    &  \\
&Item        && no        && 2       &  \\ \hline
\end{tabular*}\\
\vspace{.5cm}

\newcolumntype{;}{X@{}}% dummy column
\begin{tabularx}{7cm}{|+;>{\bfseries}l;|;^c;|;^c;|}
\hline\rowstyle{\bfseries}%
&            &&& property  &&& number   & \\ \hline
&Something   &&& yes       &&& 1554     & \\
&Item        &&& no        &&& 2        & \\ \hline
\end{tabularx}\\
\vspace{.5cm}

\setlength{\tabcolsep}{.52cm}
\begin{tabular}{|>{\bfseries}+l|^c|^c|}
\hline\rowstyle{\bfseries}%
            & property  & number    \\ \hline
Something   & yes       & 1554      \\
Item        & no        & 2         \\ \hline
\end{tabular}


\end{table}

\end{document}

In the code, the first table doesn't align nicely. The second and third table require the use complex code for formatting the table in the document. Where I'd rather separate the formatting from the contents. The fourth example works nicely, but requires manual tuning of tabcolsep.

How should I define a tabular environment that dynamically increases the cell margins to obtain the desired table width?

@Christoph: Then you would have to know the width of column without space to calculate the right factors for the X columns to get evenly distributed space across columns. — Heiko Oberdiek, Sep 20 '13 at 11:26
You could look at tabularx or tabulary packages, but the space added by \extracolsep is evenly distributed if you add a final @{} after the | to match the @{} at the start. (or use ! instead of @ so it does not remove the \tabcolsep at that point. — David Carlisle, Sep 20 '13 at 11:28
It always helps if you post a small complete example document that shows the problem. — David Carlisle, Sep 20 '13 at 11:29
@DavidCarlisle, I could not get your suggestions to work. The '!' version does compile, but the only change is small lines sticking out at the left. Adding '@{}' also does not improve the situation. I did add a full example document now. — GrowMyHair, Sep 20 '13 at 11:52

score 4 · Answer 1 · edited Jun 12 '17 at 17:51

Usually LaTeX does not use TeX's \tabskip to set the space between the columns, but it uses the dimen register \tabcolsep. The latter is also inserted between a column and the vertical line opposite to \tabskip that is only inserted between columns. \extracolsep sets \tabcolsep. The example in the question contains a table with three columns, six \tabcolsep and two \tabskip.

Therefore a workaround is the use of dummy columns:

\documentclass[a5paper]{article}

\usepackage{array}
\newcolumntype{;}{l@{}}% dummy column

\begin{document}

\noindent
\begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}|;l;|c;|c;|}
\hline
&     && 1   && 2  &\\ \hline
& a   && x   && 15 &\\
& b   && y   && 2  &\\ \hline
\end{tabular*}

\end{document}

Variant with \rowstyle:

\documentclass[a5paper]{article}

\usepackage{array}
\newcolumntype{;}{l@{}}% dummy column

\newcolumntype{+}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{^}{>{\currentrowstyle}}
\newcommand*{\rowstyle}[1]{%
  \gdef\currentrowstyle{#1}%
  #1\ignorespaces
}

\begin{document}

\noindent
\begin{tabular*}{\linewidth}{@{\extracolsep{\fill}}|+;>{\bfseries}l;|^c;|^c;|}
\hline
\rowstyle{\bfseries}%
&     && 1   && 2  &\\ \hline
& a   && x   && 15 &\\
& b   && y   && 2  &\\ \hline
\end{tabular*}

\end{document}

$Result tabular* with \rowstyle$

Another workaround is tabularx with dummy X columns. These columns are the place where the evenly distributed space should go:

\documentclass[a5paper]{article}

\usepackage{tabularx}
\usepackage{array}
\newcolumntype{;}{X@{}}% dummy column

\begin{document}

\noindent
\begin{tabularx}{\linewidth}{|;l;|;c;|;c;|}
\hline
&     &&& 1   &&& 2  &\\ \hline
& a   &&& x   &&& 15 &\\
& b   &&& y   &&& 2  &\\ \hline
\end{tabularx}

\end{document}

Variant with \rowstyle:

\documentclass[a5paper]{article}

\usepackage{tabularx}
\usepackage{array}
\newcolumntype{;}{X@{}}% dummy column

\newcolumntype{+}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{^}{>{\currentrowstyle}}
\newcommand*{\rowstyle}[1]{%
  \gdef\currentrowstyle{#1}%
  #1\ignorespaces
}

\begin{document}

\noindent
\begin{tabularx}{\linewidth}{|+;>{\bfseries}l;|;^c;|;^c;|}
\hline
\rowstyle{\bfseries}%
&     &&& 1   &&& 2  &\\ \hline
& a   &&& x   &&& 15 &\\
& b   &&& y   &&& 2  &\\ \hline
\end{tabularx}

\end{document}

$Result tabularx with \rowstyle$

Thanks for the suggestions. I tried both and adapted my example to include them. They do get me nice alignment, but the '\rowstyle' command no longer works. Moveover, they complicate the code for writing the table quite a bit. — GrowMyHair, Sep 20 '13 at 12:48

David Carlisle · Answer 2 · 2017-06-03T09:44:32.587

The space added by \extracolsep is added evenly between the columns but the vertical rules are not placed in the centre of that space, but before it, so one option is simply don't use vertical rules. Alternatively tx or ty might come to your rescue:

See Is it possible to make an underfull tabulary spread out?

for the TY patch.

enter image description here

\documentclass{book}
\usepackage{array,tabularx,tabulary}
\newcolumntype{+}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{^}{>{\currentrowstyle}}
\newcommand{\rowstyle}[1]{\gdef\currentrowstyle{#1}%
  #1\ignorespaces} 
\tymin0pt
\makeatletter


\def\foo#1\def\TY@ratio#2#3!!{
\def\TY@checkmin{#1%
 \@tempdima\TY@ratio\TY@tablewidth
 \ifdim\@tempdima>\TY@linewidth
  \advance\@tempdima-\TY@linewidth
  \Gscale@div\@tempb\@tempdima\TY@tablewidth
  \@tempdimb\TY@ratio\p@
  \advance\@tempdimb-\@tempb\p@
  \edef\TY@ratio{\strip@pt\@tempdimb}%
\fi
#3}}
\expandafter\foo\TY@checkmin!!



\makeatother

\makeatother

\makeatletter
\g@addto@macro\@floatboxreset{\centering\sffamily\small}
\makeatother

\begin{document}

\begin{table}
\begin{tabular*}{.95\textwidth}{@{\extracolsep{\fill}}|>{\bfseries}+l|^c|^c|}
\hline\rowstyle{\bfseries}%
    & 1   & 2 \\ \hline
a   & x   & 15\\
b   & y   & 2 \\ \hline
\end{tabular*}

\bigskip
\begin{tabular*}{.95\textwidth}{@{\extracolsep{\fill}}>{\bfseries}+l^c^c@{}}
\hline\rowstyle{\bfseries}%
    & 1   & 2 \\ \hline
a   & x   & 15\\
b   & y   & 2 \\ \hline
\end{tabular*}

\bigskip

\begin{tabularx}{.95\textwidth}{@{}|>{\bfseries}+l|^>{\centering\arraybackslash}X|^>{\centering\arraybackslash}X|@{}}
\hline\rowstyle{\bfseries}%
    & 1   & 2 \\ \hline
a   & x   & 15\\
b   & y   & 2 \\ \hline
\end{tabularx}

\bigskip

\begin{tabulary}{.95\textwidth}{|>{\bfseries}+L|^C|+C|}
\hline\rowstyle{\bfseries}%
    & 1   & 2 \\ \hline
a   & x   & 15\\
b   & y   & 2 \\ \hline
\end{tabulary}
\end{table}

\end{document}

Fixed table width with even alignment

2 Answers2