I'm trying to make a longtable and use some R tools for generating them. The problem is that when a long table has more than one columns, it creates double headers, as shown here: https://stackoverflow.com/questions/20552459/excessive-elements-in-latex-longtable-output-when-more-than-one-row-is-used-in-h. I use LyX to generate the output.
This is one-column code:
\begin{document}
\setlongtables
\begin{longtable}{r}\caption{Title} \tabularnewline
\hline\hline
\multicolumn{1}{c}{X1.10}\tabularnewline
\hline
\endfirsthead\caption[]{\em (continued)} \tabularnewline
\hline
\multicolumn{1}{c}{X1.10}\tabularnewline
\hline
\endhead
\hline
\endfoot
\label{data.frame}
$ 1$\tabularnewline
$ 2$\tabularnewline
$ 3$\tabularnewline
$ 4$\tabularnewline
$ 5$\tabularnewline
$ 6$\tabularnewline
$ 7$\tabularnewline
$ 8$\tabularnewline
$ 9$\tabularnewline
$10$\tabularnewline
\hline
\end{longtable}
\end{document}
And this is a two-column table:
\begin{document}
\setlongtables
\begin{longtable}{rr}\caption{Title} \tabularnewline
\hline\hline
\multicolumn{1}{c}{X1.10}&\multicolumn{1}{c}{X10.1}\tabularnewline
\hline
\endfirsthead\caption[]{\em (continued)} \tabularnewline
\hline
\multicolumn{1}{c}{X1.10}&\multicolumn{1}{c}{X10.1}\tabularnewline
\hline
\endhead
\hline
\endfoot
\label{data.frame}
$ 1$&$10$\tabularnewline
$ 2$&$ 9$\tabularnewline
$ 3$&$ 8$\tabularnewline
$ 4$&$ 7$\tabularnewline
$ 5$&$ 6$\tabularnewline
$ 6$&$ 5$\tabularnewline
$ 7$&$ 4$\tabularnewline
$ 8$&$ 3$\tabularnewline
$ 9$&$ 2$\tabularnewline
$10$&$ 1$\tabularnewline
\hline
\end{longtable}
\end{document}
What's wrong with the latter one? Judging from the code, they are identical.
UPDATE
That was LyX: when my .tex file was imported in LyX, it created additional code (the header), so that further processing went wrong.