剧情结尾被切断

Question

xmin无论如何设置，我的一块地的大约 1/10 都会被两侧切断xmax。如何防止这种情况发生？

\documentclass{standalone}
\usepackage{tikz,pgfplots}

\begin{document}

        \begin{tikzpicture} \pgfplotsset{scale only axis}
        \begin{axis}[ymin=0,xmin=0,xmax=1,
        axis y line*=left,
        width=13cm,height=7cm,tick align=center]
        \addplot[smooth]
        coordinates{
            (0.0001,2)
            (0.999999,2)    
        };  
        \end{axis}

        \begin{axis}[axis y line*=right,
        axis x line=none,width=13cm,height=7cm]

        \addplot[dotted]
        coordinates{
            (0.0001, 1)
            (0.99999,1)};   
        \end{axis}
        \end{tikzpicture}

\end{document}