pgfplots 填充分层问题

Question

我使用ticklabel style={fill=white}来pgfplots确保刻度标签在网格线中仍然清晰可读。但是，当我使用 时，似乎fillbetweensticklabel会在填充之后绘制，因此会显示在图表顶部。如果我使用命令\draw绘制矩形，则矩形最终会显示在 的顶部ticklabel，这正是我想要的。

下面是我正在使用的代码和图

\begin{tikzpicture}
    \begin{axis}[
        xmin=-2,xmax=2,
        ymin=-1,ymax=2,
        x=1cm,y=1cm,
        axis lines=middle,
        grid=both,
        minor tick num=0,
        enlargelimits={abs=0.5},
        ticklabel style={font=\tiny,fill=white},
    ]

        \addplot[name path=f,no marks,mypink,thick,domain=-2:2, samples=25, draw=none] ({x},{x*x});
        \addplot[no marks,thick,domain=-2:2, samples=25,smooth] ({x},{x*x});
        \addplot[name path=g, no marks,thick,domain=-5:5, samples=2] ({x},{1.5});
        \addplot [thick, color=blue, fill=blue, fill opacity=0.5] fill between [of=f and g, split];

        \draw[fill=blue,opacity=0.5] (-1.5,-.5) rectangle(-.5,.5);

    \end{axis}
\end{tikzpicture}

Answer 1

这是因为默认情况下fill between，内容绘制在图层上pre main，其余内容也绘制在图层上main。要获得所需的结果，只需使用预定义图层即可standard。

（请注意，我还允许自己“优化”\addplot一下您的命令。有关更多详细信息，请查看代码中的注释。）

我还包括了仅填充“封闭”区域的额外要求，如该答案下方的评论中所写。

\documentclass[border=5pt]{standalone}
\usepackage{pgfplots}
    \usepgfplotslibrary{fillbetween}
    \pgfplotsset{compat=1.11}
\begin{document}
    \begin{tikzpicture}
        \begin{axis}[
            set layers=standard,    % <-- added
            xmin=-2,xmax=2,
            ymin=-1,ymax=2,
            x=1cm,y=1cm,
            axis lines=middle,
            grid=both,
            minor tick num=0,
            enlargelimits={abs=0.5},
            ticklabel style={font=\tiny,fill=white},
            no markers,             % <-- moved common `\addplot' options here
            smooth,                 % <-- added, because it looks a bit "smoother"
        ]

            % combined first two `\addplot's to this one
            % and you don't need a parametric plot here
            \addplot [name path=f,draw=black,thick,domain=-2:2, samples=25] {x^2};
            \addplot [name path=g,thick,domain=-5:5, samples=2] {1.5};

            \addplot [fill=none] fill between [
                    of=f and g,
                    split,
                    % draw only selected ones:
                    % every segment no 0/.style: invisible
                    every segment no 1/.style={
                        fill=blue,opacity=0.5
                    },
                    % every segment no 2/.style: invisible
                ];

            \draw[fill=blue,opacity=0.5] (-1.5,-.5) rectangle(-.5,.5);

        \end{axis}
    \end{tikzpicture}
\end{document}