\begin{table}
\caption{Schechter and double-power law parameters}
\label{Tab4}
\begin{tabular}{lcc|cccc}
\hline
\noalign{\smallskip}
         & \multicolumn{2}{c|}{Schechter} &
\multicolumn{4}{c}{Double-power-law} 
\\
\noalign{\smallskip}
  Sample & $\alpha$ & $M^*$ &
  $\alpha$ & $\gamma$ & $\delta$ & $M^*$ \\ 
\hline
\noalign{\smallskip}
  First-ranked galaxies& $-0.557\pm 0.031$ & $-19.95\pm 0.04$ & 
  $-0.802\pm 0.015$ & $2.44\pm 0.13$       & $-6.22\pm 0.40$ & $-20.97\pm 0.07$
\\
  Satellite galaxies   & $-1.131\pm 0.026$ & $-19.18\pm 0.04$ & 
  $-1.231\pm 0.031$ & $1.73\pm 0.19$       & $-7.95\pm 1.84$  & $-20.44\pm 0.31$
\\
  Group galaxies       & $-1.197\pm 0.020$ & $-19.96\pm 0.04$ & 
  $-1.177\pm 0.044$  & $1.23\pm 0.19$      & $-8.43\pm 3.53$  & $-21.44\pm 0.72$
\\
  First-ranked+Isolated& $-1.031\pm 0.016$ & $-19.93\pm 0.03$ & 
  $-1.211\pm 0.013$ & $2.14\pm 0.14$   & $-5.64\pm 0.48$ & $-20.69\pm 0.11$ \\
  Isolated galaxies    & $-1.058\pm 0.017$ & $-19.76\pm 0.03$ & 
  $-1.258\pm 0.013$ & $2.37\pm 0.17$   & $-5.35\pm 0.41$ & $-20.43\pm 0.10$   \\
  All galaxies         & $-1.098\pm 0.012$ & $-19.77\pm 0.02$ & 
  $-1.200\pm 0.022$  & $1.66\pm 0.15$   & $-5.71\pm 0.71$ & $-20.60\pm 0.20$ \\
  Groups               & $-0.928\pm 0.020$ & $-22.05\pm 0.04$   & 
  $-0.734\pm 0.045$  & $0.89\pm 0.10$   & $-5.98\pm 0.76$ & $-23.33\pm 0.60$ \\
\hline
\end{tabular}
\par
\medskip
$M^*$ is in units of mag$-5\log(h)$.
\end{table}