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使用 Tikz 为图形绘制阴影区域？

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使用 Tikz 为图形绘制阴影区域？

我想在此图表中为标有 A、B、C、D 的区域添加阴影。

\begin{tikzpicture}
 \begin{axis}[
   xmin = 0, xmax = 1000,
   ymin = 12, ymax = 16,
   xlabel=$Q$,
   ylabel=$P$,
  ]
  \addplot[name path global=supply, domain=0:1000, red] { 0.00325*x + 12.5125 };
  \addplot[name path global=demand, domain=0:1000, blue] { -0.013*x + 22.75 };
  \addplot[name path global=world, domain=0:1000, black] { 13 };
  \addplot[name path global=tariff, domain=0:1000, green] { 13.65 };


  \node at (axis cs:100, 13.3) {$A$};
  \node at (axis cs:300, 13.3) {$B$};
  \node at (axis cs:550, 13.3) {$C$};
  \node at (axis cs:720, 13.1) {$D$};

  \vasymptote[dashed]{350}
  \vasymptote[dashed]{700}

  \legend{$Supply$, $Demand$, $P_{world}$, $P_{tariff}$}

 \end{axis}
\end{tikzpicture}

输出如下： 在此处输入图片描述

我想要为区域 A、B、C、D 着色——例如，用绿色填充梯形 A，用蓝色填充三角形 B，用橙色填充矩形 C，用紫色填充三角形 D。

\vasymptote 在我的序言中定义：

\usepackage{pgfplots}
\usepackage{tkz-fct}
\usetikzlibrary{intersections}


\newcommand{\vasymptote}[2][]{
    \draw [densely dashed,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
}

\newcommand{\gettikzxy}[3]{%
  \tikz@scan@one@point\pgfutil@firstofone#1\relax
  \edef#2{\the\pgf@x}%
  \edef#3{\the\pgf@y}%
}

\pgfplotsset{
    every axis/.append style={
        scale only axis,
        width=1.0\columnwidth,
    },
    /tikz/every picture/.append style={
        trim axis left,
        trim axis right,
    }
}

\def\Dimline[#1][#2][#3][#4]{
\begin{scope}[thin, >=stealth'] % redefine as flechas
\draw let \p1=#1, \p2=#2, \n0={veclen(\x2-\x1,\y2-\y1)} in [|<->|,
decoration={markings,mark=at position .5 with {\node[#3] at (0,0)
{#4};},
},
postaction=decorate] #1 -- #2 ;
\end{scope}
}

答案1

这是一条建议。我修改了\vasymptote第二个强制参数，即路径的名称。然后我name intersections给线条之间的各个交叉点赋予节点名称，最后添加\fill颜色。我使用backgrounds库在背景层上添加此填充，避免部分覆盖情节线条。

此外，我建议您不要以数学模式编写前两个图例条目，并且以直立字体编写最后两个图例条目中的下标。

\documentclass[border=10mm]{standalone}
\usepackage{pgfplots}
\usepackage{tkz-fct}
\usetikzlibrary{intersections,backgrounds}


\newcommand{\vasymptote}[3][]{
    \draw [densely dashed,name path=#3,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
}

\newcommand{\gettikzxy}[3]{%
  \tikz@scan@one@point\pgfutil@firstofone#1\relax
  \edef#2{\the\pgf@x}%
  \edef#3{\the\pgf@y}%
}

\pgfplotsset{
    every axis/.append style={
        scale only axis,
        width=1.0\columnwidth,
    },
    /tikz/every picture/.append style={
        trim axis left,
        trim axis right,
    }
}

\def\Dimline[#1][#2][#3][#4]{
\begin{scope}[thin, >=stealth'] % redefine as flechas
\draw let \p1=#1, \p2=#2, \n0={veclen(\x2-\x1,\y2-\y1)} in [|<->|,
decoration={markings,mark=at position .5 with {\node[#3] at (0,0)
{#4};},
},
postaction=decorate] #1 -- #2 ;
\end{scope}
}
\begin{document}

\begin{tikzpicture}
 \begin{axis}[
   xmin = 0, xmax = 1000,
   ymin = 12, ymax = 16,
   xlabel=$Q$,
   ylabel=$P$,
  ]
  \addplot[name path global=supply, domain=0:1000, red] { 0.00325*x + 12.5125 };
  \addplot[name path global=demand, domain=0:1000, blue] { -0.013*x + 22.75 };
  \addplot[name path global=world, domain=0:1000, black] { 13 };
  \addplot[name path global=tariff, domain=0:1000, green] { 13.65 };


  \node at (axis cs:100, 13.3) {$A$};
  \node at (axis cs:300, 13.3) {$B$};
  \node at (axis cs:550, 13.3) {$C$};
  \node at (axis cs:720, 13.1) {$D$};

  \vasymptote[dashed]{350}{first}
  \vasymptote[dashed]{700}{second}

  \legend{Supply, Demand, $P_\mathrm{world}$, $P_\mathrm{tariff}$}

  \path [name intersections={of=supply and world, by={a}},
         name intersections={of=supply and tariff, by={b}},
         name intersections={of=first and world, by={c}},
         name intersections={of=second and world, by={d}},
         name intersections={of=demand and tariff, by={e}},
         name intersections={of=demand and world, by={f}}];

 \begin{scope}[on background layer]
  \fill [blue,opacity=.3] (axis cs:0,13) -- (axis cs:0,13.65) -- (b) -- (a) -- cycle;
  \fill [red,opacity=.3] (a) -- (b) -- (c) -- cycle;
  \fill [green,opacity=.3] (b) -- (c) -- (d) -- (e) -- cycle;
  \fill [purple,opacity=.3] (e) -- (d) -- (f) -- cycle;
 \end{scope}
 \end{axis}

\end{tikzpicture}

\end{document}

在此处输入图片描述

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