begin{figure*}[!ht]
 centering
subfigure[]{%label{fig:ch4cyclic}
 includegraphics[width=0.45linewidth]{Scenario1-path.pdf}label{fig:sc1desvsact}}
 ~
subfigure[]{%label{fig:ch4cyclic}
 includegraphics[width=0.45linewidth,trim=300 0 0 0,clip]{Scenario1-err.pdf}label{fig:sc1err}}
 caption{Comparison between desired and actual performance (a) and observed errors (b) in the first scenario}
 label{fig:sc1}
 end{figure*}