\begin{tikzpicture}
\pgfplotsset{filter discard warning=false}
\begin{axis}[
%  legend cell align=left,
%  height=0.4\textheight,
  xlabel shift = 0.05in,
  ylabel shift = -0.05in,
  xlabel={Quantity ($q$)},
  ylabel={Price ($p$)},
  axis line style={->},
  axis x line* = bottom,
  axis y line = left,
  grid = major,
  grid style={dashed, gray!30},
  xmin = 0,
  xmax = 3,
  ymin = 0.8,
  ymax = 1.4]
\addplot[color=red,  thick, solid] table [y=p, x=d]{figures/figure9.data};
\addplot[color=blue, thick, dashed] table [y=p, x=s]{figures/figure9.data};
\addplot[color=red,  thin,  solid] table [y=p, x=q]{figures/figure9.data};
\addplot[color=blue, thin,  dashed] table [y=pref, x=q]{figures/figure9.data};
\draw [color=black, thin, dashed] (axis cs:2.48832,0.8) -- (axis cs:2.48832,1.18) -- (axis cs:0,1.18);
\node[circle,label={135:$b$},fill=black,scale=0.3] at (axis cs:1,1)     {};
\node[circle,label={ 45:$a$},fill=black,scale=0.3] at (axis cs:1,1.2)   {};
\node[circle,label={-135:$c$},fill=black,scale=0.3] at (axis cs:2.48832,1) {};
\node[circle,label={-45:$d$},fill=black,scale=0.3] at (axis cs:2.48832,1.18) {};
\end{axis}
\end{tikzpicture}
