Tikz：多目标优化

Question

我正在尝试创建以下图表：

我正在尝试使用此代码，但我无法创建这些区域。

\begin{tikzpicture}
\draw [fill=black!15] plot  %
coordinates {(3.7,0.35) (3.7,3.25) (0.75,0.35)};
\draw [fill=black!30] plot  %
coordinates {(2.75,0.9) (2.75,3.5) (0.75,0.9)};
\draw[->] (0,0) -- (5,0) node[anchor=north] {$C$};
\draw   (1,0.9) node[anchor=north] {$(C_o,R_r)$}
    (2.75,2.75) node[anchor=west] {$(C_r,R_o)$}
    (3.7,0.35) node[anchor=west] {$(C_i,R_i)$};
\draw[->] (0,0) -- (0,4) node[anchor=east] {$R$};
\draw[thick,->] (3.7,0.35) -- (1,0.9);
\draw[thick,->] (3.7,0.35) -- (2.75,2.75);
\draw [gray] (2.75,2.75) arc [radius=1.52, start angle=111.6, end angle= 
168.49];
\end{tikzpicture}

任何人都可以帮助我吗？

非常感谢您提前，

胡

Answer 1

只是原始草图：

\documentclass[tikz,border=2mm]{standalone}

\begin{document}

\begin{tikzpicture}
\draw[->] (-1,0) -- (5,0) node[anchor=north] {$C$};
\draw[->] (0,-1) -- (0,4) node[anchor=east] {$R$};
\fill [gray!15] plot coordinates {(3.7,0.35) (3.2,3.2) (0.5,0.8)};
\fill [gray!15] plot [smooth cycle] coordinates {(2.7,1.35) (3.2,3.2) (1.5,2.6) (0.5,0.8)};
\fill [gray!30] plot [smooth cycle] coordinates {(3.4,0.65) (2.7,2.9) (2,2.6) (1.2,1.75) (1,0.9)};
\filldraw (3.7,0.35) circle (1.5pt);
\filldraw (2.75,2.75) circle (1.5pt);
\filldraw (1,0.9) circle (1.5pt);
\draw  (1,0.9) node[anchor=north] {$(C_o,R_r)$}
(2.75,2.75) node[anchor=west] {$(C_r,R_o)$}
(3.7,0.35) node[anchor=west] {$(C_i,R_i)$};
\draw[thick,->] (3.7,0.35) -- (1,0.9);
\draw[thick,->] (3.7,0.35) -- (2.75,2.75);
\draw[dashed] (1,0.9) arc [radius=2.2, start angle=171.6, end angle=101];
\end{tikzpicture}

\end{document}

我使用\fill [gray!30]表示较暗的区域，两个\fill [gray!15]表示较浅的区域（两个，以便更好地勾画直边和曲线边缘）。

三个点(1,0.9)，(3.7,0.35)和(2.75,2.75)来自您的代码，在输入代码之前，应该在纸上更仔细地绘制其他三个点。