Having the following siunitx table code in LyX, for each occurrence of \toprule and \midrule I obtain an error message:
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g.,
\hobx'), type
I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
I correctly imported siunitx in the preamble. TexLive version: 2012.10.20121205_r28449.fc18
LaTeX code:
\centering
\sisetup{output-decimal-marker={,}}
\begin{tabular}{ccS}
\toprule
{Dimensione finestra} & {Perdita} & {Tempo}\\
{} & {} & {(secondi)}\\
\midrule
10 & 0$\%$ & 121\\
\midrule
10 & 10$\%$ & 127\\
\midrule
10 & 20$\%$ & 176\\
\midrule
10 & 30$\%$ & 257\\
\midrule
10 & 40$\%$ & 442\\
\midrule
10 & 50$\%$ & 780\\
\midrule
10 & 60$\%$ & 1226\\
\midrule
10 & 70$\%$ & 1469\\
\midrule
10 & 80$\%$ & 1904 \\
\midrule
10 & 90$\%$ & 3234 \\
\midrule
50 & 0$\%$ & 46 \\
\midrule
50 & 10$\%$ &109 \\
\midrule
50 & 20$\%$ &146 \\
\midrule
50 & 30$\%$ &202 \\
\midrule
50 & 40$\%$ &257 \\
\midrule
50 & 50$\%$ &373 \\
\midrule
50 & 60$\%$ &544 \\
\midrule
50 & 70$\%$ &760 \\
\midrule
50 & 80$\%$ &1356 \\
\midrule
50 & 90$\%$ &6588 \\
\midrule
100 & 0$\%$ &76 \\
\midrule
100 & 10$\%$ &91 \\
\midrule
100 & 20$\%$ &109 \\
\midrule
100 & 30$\%$ &146 \\
\midrule
100 & 40$\%$ &180 \\
\midrule
100 & 50$\%$ &297 \\
\midrule
100 & 60$\%$ &414 \\
\midrule
100 & 70$\%$ &585 \\
\midrule
100 & 80$\%$ &1355 \\
\midrule
100 & 90$\%$ &4326 \\
\bottomrule
\end{tabular}
Adding
\usepackage{booktabs}
solved the problem :O