Redefinition of tabularx column not applying to all columns

Question

I obeserve a strange behaviour when trying to get text vertically centered in tabularx cells. According to a suggestion, I tried \renewcommand{\tabularxcolumn}[1]{m{#1}} which works so far as it goes. But I have three columns, only two of which appear to be affected. Here is my MWE

\documentclass{article}
\usepackage{tabularx,colortbl,xcolor}
\usepackage[utf8]{inputenc}
\begin{document}
\renewcommand{\tabularxcolumn}[1]{m{#1}}
   \begin{center}
      \begin{tabularx}{\textwidth}{|c|X|X|}
         \hline
         Chomsky-Typ & Name der Sprachfamilie & Automaten \\
         \hline\hline\hline
         0 & \cellcolor{lightgray!20}rekursiv aufzählbar & \cellcolor{lightgray!20}(N)DTM \\[1em]
         \hline
         \cellcolor{lightgray!20}1 & \cellcolor{lightgray!20}kontext-sensitiv & NLBA \\[1em]
         \hline
         \cellcolor{lightgray!20}3 & regulär & \cellcolor{lightgray!20}(N)DEA \\[1em]
         \hline
         hu & ha & he \\[1em]
         \hline
      \end{tabularx}
   \end{center}
\end{document}

Here is the output. As you see, the right X coulumn is unaffected.

I am at a loss. What am I missing?

score 3 · Accepted Answer · edited Apr 13 '17 at 12:35

This is due to the extra space of \\[1em] being effectively added to the text within the last cell in the row, thus preventing that cell from being centered - see here.

Thus in order to get your content centered and be able to specify row height, you need to add another, empty, column to your table, like so:

\documentclass{article}
\usepackage{tabularx,colortbl,xcolor}
\usepackage[utf8]{inputenc}
\begin{document}
\newlength\origtabcolsep
\origtabcolsep=\tabcolsep
\tabcolsep=0pt
\renewcommand{\tabularxcolumn}[1]{m{#1}}
\newcolumntype{e}{>{\hsize=0pt}X}
\newcolumntype{x}{>{\hskip\origtabcolsep}X<{\hskip\origtabcolsep}}
\newcolumntype{C}{>{\hskip\origtabcolsep}c<{\hskip\origtabcolsep}}
   \begin{center}
      \begin{tabularx}{\textwidth}{|C|x|xe|}
         \hline
         Chomsky-Typ & Name der Sprachfamilie & Automaten &\\
         \hline\hline\hline
         0 & \cellcolor{lightgray!20}rekursiv aufzählbar & \cellcolor{lightgray!20}(N)DTM &\\[1em]
         \hline
         \cellcolor{lightgray!20}1 & \cellcolor{lightgray!20}kontext-sensitiv & NLBA &\\[1em]
         \hline
         \cellcolor{lightgray!20}3 & regulär & \cellcolor{lightgray!20}(N)DEA & \\[1em]
         \hline
         hu & ha & he &\\[1em]
         \hline
      \end{tabularx}
   \end{center}
\tabcolsep=\origtabcolsep
\end{document}

output table

The specification of the empty column was inspired by this. Edit: I fixed the white space at the right hand side of the table by introducing new column types allowing to set \tabcolsep to 0pt temporarily.

This does do the trick. One would think there was a simpler solution for this. — oarfish, Aug 09 '14 at 21:13

score 0 · Answer 2 · answered Aug 09 '14 at 16:12

I suggest another approach: with the cellspace package, define a minimal vertical spacing between the top of a cell and the above cell, and similarly aminimal spacing between the bottom of a cell and the top of the below cell. There remains to prefix the column specifier with S. It works by default with the l, r, c specifier, and with the X type if you dclare so in preamble. Here is an example (values to be adjusted to your taste):

\documentclass{article}
\usepackage{tabularx,colortbl,xcolor}
\usepackage[utf8]{inputenc}
\renewcommand{\tabularxcolumn}[1]{m{#1}}

\usepackage{cellspace}
\setlength\cellspacetoplimit{10pt}
\setlength\cellspacebottomlimit{10pt}
\addparagraphcolumntypes{{X}}


\begin{document}

   \begin{center}
      \begin{tabularx}{\textwidth}{|c|X|S{X}|}
         \hline
         Chomsky-Typ & Name der Sprachfamilie & Automaten    \\
         \hline\hline\hline
         0 & \cellcolor{lightgray!20}rekursiv aufzählbar & \cellcolor{lightgray!20}(N)DTM  \\
         \hline
         \cellcolor{lightgray!20}1 & \cellcolor{lightgray!20}kontext-sensitiv & NLBA \\
         \hline
         \cellcolor{lightgray!20}3 & regulär & \cellcolor{lightgray!20}(N)DEA \\
         \hline
         hu & ha & he \\
         \hline
      \end{tabularx}
   \end{center}

\end{document}

enter image description here

that seems a good solution - any way to prevent it from also affecting the header row? or to have rows of different/arbitrary height? — greyshade, Aug 09 '14 at 16:16
I wonder that too. The intent is to have the header row have a different height. — oarfish, Aug 09 '14 at 20:34
Use \multicolumn{1}{l|}{Automate} to neutralize the effect of the S prefix (and possibly add \set length{\extrarowheight}{xxx pt}) to not have a too great contrast in heights. — Bernard, Aug 09 '14 at 20:51
@greyshade: no, cellspace does not allow to change the minimal vertical spacings. But you can increase row heights by inserting invisible rules with predefined height and depth in a cell. — Bernard, Aug 09 '14 at 20:55

Redefinition of tabularx column not applying to all columns

2 Answers2