\input{figures/figure-theme.tex}
\begin{center}
\begin{tikzpicture}[aml figure]
\amlfigurepalette
\begin{axis}[
  aml axis,
  width=8.4cm,height=8.0cm,
  xlabel={$x_1$}, ylabel={$x_2$},
  xmin=0,xmax=8,ymin=0,ymax=8,
  xtick={0,1,2,3,4,5,6,7,8},
  ytick={0,1,2,3,4,5,6,7,8},
  legend style={at={(0.5,1.08)},anchor=south,draw=none,legend columns=2},
]
\addplot[only marks,blue,very thick,mark=square] coordinates{
  (0.6,5.7) (0.9,4.8) (1.1,6.8) (1.5,5.2) (1.8,7.1)
  (2.2,6.0) (2.4,7.5) (2.8,5.6) (3.2,6.4) (3.5,7.8)
  (3.7,6.9) (4.0,7.3) (4.3,6.2) (4.6,7.6)};
\addlegendentry{食物类}
\addplot[only marks,red,very thick,mark=x,mark size=4pt] coordinates{
  (3.0,0.8) (3.4,1.5) (3.8,2.1) (4.1,1.1) (4.5,2.4)
  (4.9,1.7) (5.2,0.9) (5.6,2.7) (6.0,1.3) (6.5,3.0)
  (6.9,1.1) (7.3,4.1)};
\addlegendentry{非食物类}
\addplot[FigureInk,semithick,domain=0:8]{1.55*x-1.0};
\addplot[FigureTeal,semithick,dashed,domain=0:8]{0.55*x+1.6};
\addplot[FigureGold,semithick,dash dot,domain=0:8]{-0.35*x+5.0};
\node[rotate=56,anchor=south] at (axis cs:2.0,2.2) {\footnotesize 超平面 1};
\node[rotate=29,anchor=south] at (axis cs:5.7,4.9) {\footnotesize 超平面 2};
\node[rotate=-20,anchor=south] at (axis cs:2.3,4.0) {\footnotesize 超平面 3};
\end{axis}
\end{tikzpicture}
\end{center}
