\begin{table}%t1
%\centering
\par
 \small \caption{Mean absolute errors on the evaluation set of 908 spectra in the SS
    model for different numbers of PCs retained in the reconstruction. (As PCA
    is done separately on the blue and red regions, the total number of inputs 
    is twice the number of PCs.).}\label{t_SS}
    \leavevmode
        \begin{tabular}[h]{llll}
        \hline\hline 
        PCs& $E_{\log ~T_{\rm eff}}$&$E_{\log ~g}$& $E_{\rm [Fe/H]}$ \\
        \hline 
        5    &   0.0087 & 0.1264 & 0.1558 \\
        25   &   0.0036 & 0.0245 & 0.0327 \\
        100  &   0.0030 & 0.0251 & 0.0269 \\
        908  &   0.0133 & 0.2087 & 0.2308 \\
       \hline 
       \end{tabular}
\end{table}