我怎样才能在这个线图中为 x 轴留出额外的空间？

Question

我正在尝试构建如下线图。我需要额外的空间来放置符号 x 轴，以便添加符号 $\tau=\bar{Y}{1,1}-\bar{Y}括号旁边有 {1,0}$。有什么办法吗？谢谢，

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\begin{document}
\begin{tikzpicture}
\begin{axis}[axis lines=left,  ylabel={$BMI$}, ymax=90,ymin=30, xtick=\empty, ytick=\empty, 
    legend style={at={(0.5,0.2),anchor=north}
        },
    symbolic x coords={Baseline(T0), PostRandomization(T1)}, xtick=data]
    \addplot[mark=diamond*,thick,red] coordinates {
        (Baseline(T0),80) (PostRandomization(T1),70)};
    \addlegendentry{Control}
    \addplot[mark=o,mark options={solid},blue,thick,dashed] coordinates {
        (Baseline(T0),79.5) (PostRandomization(T1),50) };
    \addlegendentry{Treatment}
    \draw [thick,decoration={brace,mirror,raise=5pt},decorate] 
      (axis cs:{PostRandomization(T1)},70) --
        node[below=5pt]{$\tau=\bar{Y}_{1,1}-\bar{Y}_{1,0}$} 
      (axis cs:{PostRandomization(T1)},50);
\end{axis}
\end{tikzpicture}
\end{document}

Answer 1

我只需将支架放在轴的外侧和右侧即可。

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
\begin{document}
\begin{tikzpicture}
\begin{axis}[axis lines=left,  ylabel={$BMI$}, ymax=90,ymin=30, xtick=\empty, ytick=\empty, 
    legend style={at={(0.5,0.2),anchor=north}
        },
    symbolic x coords={Baseline(T0), PostRandomization(T1)}, xtick=data]
    \addplot[mark=diamond*,thick,red] coordinates {
        (Baseline(T0),80) (PostRandomization(T1),70)};
    \addlegendentry{Control}
    \addplot[mark=o,mark options={solid},blue,thick,dashed] coordinates {
        (Baseline(T0),79.5) (PostRandomization(T1),50) };
    \addlegendentry{Treatment}
    \path (axis cs:{PostRandomization(T1)},70) coordinate(p1)
        (axis cs:{PostRandomization(T1)},50)  coordinate(p2);
\end{axis}
\draw [thick,decoration={brace,raise=2pt},decorate] 
  (p1) --
    node[right=3pt]{$\tau=\bar{Y}_{1,1}-\bar{Y}_{1,0}$} 
  (p2);
\end{tikzpicture}
\end{document}