I'd like to put 4 x-axis on a same plot, with different scale. y-axis will be the same.
I'd try to put several \begin{axis} ... \end{axis}, but they appeared on the same location. Here, I tryed to put some fake x-axis, but it's pretty hard to do a good job.
If necessary, I can apply a factor on my data.
Does anybody have an idea to help me?
\documentclass[10pt]{article}
\usepackage{pgfplots}
\usepackage{subcaption}
\begin{document}
\begin{figure}[p]
\centering
\begin{tikzpicture}
\tikzstyle{every node}=[font=\small]
\begin{axis}[height=0.8\textwidth,width=0.8\textwidth,
axis lines=left, enlarge x limits=false,ymax=10,ymin=-0.08,
xlabel={$x_1$},
ylabel={$y$},
legend entries={$x_1$,$x_2$,$x_3$,$x_4$},
]
\addplot[draw=black,mark=o,line width=1.5pt] coordinates{(0,0)(2,2)(5,5)(8,8)(10,10)};
\addplot[,draw=red,mark=star,line width=1.5pt] coordinates{(0,0)(5,3)(10,4)(20,7)(30,10)};
\addplot[draw=blue,mark=square,line width=1.5pt] coordinates{(0,10)(10,6)(30,5)(60,3)(70,2)};
\addplot[draw=green,mark=triangle,line width=1.5pt] coordinates{(0,7)(15,10)(30,7)(100,0)};
\end{axis}
\draw[->](0,-1.5)--(8,-1.5);
\node[below] at (4,-1.5) {$x_2$};
\draw[->](0,-2.5)--(8,-2.5);
\node[below] at (4,-2.5) {$x_2$};
\draw[->](0,-3.5)--(8,-3.5);
\node[below] at (4,-3.5) {$x_2$};
\end{tikzpicture}
\end{figure}
\vfill
\end{document}

