I would like to typeset a table with a multicolumn heading only. Here is my current attempt

\documentclass{article}
\usepackage{pgfplotstable}
\usepackage{booktabs}
\usepackage{array}
\usepackage{colortbl}

\begin{document}
before row={%
\toprule
Facteurs & \multicolumn{5}{c}{Niveaux}\\
}},
every last row/.style={
after row=\bottomrule},
display columns/0/.style={string type}
]
{%
\pgfutilensuremath{\chi} & 8 & 11 & 14 & &
5 & 8 & 11 & 14 & 45 & 2.456
q & 8 & 11 & 14 & & 3
x & 8 & 11 & 14 & 5612345 & 4
b & 8 & 11 & 14 & & 5
}
\end{document}


which gives the following result:

How can I remove the headings row circled in red in the picture?

-
– Marco Daniel Aug 17 '12 at 12:11
This seems too contain the solution indeed but I failed to make it work though. if I understand correctly, I should install a new developement version of pgfplotstable? – Alfred M. Aug 17 '12 at 13:08

Starting with version 1.6 of PGFPlots (I think), a new key output empty row has become available that suppresses printing of a row. This can be used in your style:

\documentclass{article}
\usepackage{pgfplotstable}
\usepackage{booktabs}

\begin{document}
\pgfplotstabletypeset[
output empty row,
before row={%
\toprule
Facteurs & \multicolumn{5}{c}{Niveaux}\\
}
},
every last row/.style={
after row=\bottomrule
},
display columns/0/.style={string type}
]
{%
\pgfutilensuremath{\chi} & 8 & 11 & 14 & &
5 & 8 & 11 & 14 & 45 & 2.456
q & 8 & 11 & 14 & & 3
x & 8 & 11 & 14 & 5612345 & 4
b & 8 & 11 & 14 & & 5
}
\end{document}


If you're using an earlier version and can't / don't want to update, here's a slightly brutish workaround. You can add the code

\makeatletter
\pgfplotsset{
/pgfplots/table/typeset cell/.append code={%
\ifnum\c@pgfplotstable@rowindex=-1
\pgfkeyslet{/pgfplots/table/@cell content}\pgfutil@empty%
\fi
}
}
}
\makeatother


in your preamble, which makes a style omit header row available. If you use that key in \pgfplotstable, the output routine for each table cell will be amended with a check whether we're in row number -1 (the header row), and if we are, no output is generated.

\documentclass{article}
\usepackage{pgfplotstable}
\usepackage{booktabs}

\makeatletter
\pgfplotsset{
/pgfplots/table/typeset cell/.append code={%
\ifnum\c@pgfplotstable@rowindex=-1
\pgfkeyslet{/pgfplots/table/@cell content}\pgfutil@empty%
\fi
}
}
}
\makeatother

\begin{document}
\pgfplotstabletypeset[
col sep=&,
before row={%
\toprule
Facteurs & \multicolumn{5}{c}{Niveaux}\\
}
},
every last row/.style={
after row=\bottomrule
},
display columns/0/.style={string type},