我画了下面的图:
\begin{center}
\begin{tikzpicture}[scale=0.4]
\draw[ultra thick] (0,0) circle [radius=2];
\draw [thick,domain=0:60] plot ({2*cos(\x)}, {2*sin(\x)});
\draw [ultra thick,color=red,domain=0:60] plot ({2.1*cos(\x)}, {2.1*sin(\x)});
\draw[thick,dashed ]
(-4,0)--(4,0)
(0,-4)--(0,4);
\draw[ultra thick] (-8,-8)--(-5,6);
\draw[thick,dashed,] (-5.4,4)--(1,1.7);
\draw[thick] (0,0)--(1,1.7);
\node at (-2.2,2.9) {\textbf{>}};
\node at (-6.3,0) {$\bullet$};
\node at (-6.6,0) {\textbf{0}};
\node at (-5.4,4) {$\bullet$};
\node at (-5.7,4) {\textbf{x}};
\node at (4,0) {\textbf{>}};
\node at (-4,0) {\textbf{<}};
\node at (0,4) {\textbf{$\wedge$}};
\node at (0,-4) {$\vee$};
\node at (2.2,1.6) {$x_{o}$};
\end{tikzpicture}
\end{center}
但是,我想用自由曲线代替虚线,以便绘图类似于此:
答案1
有三种可能性;其中两种使用out=
,in=
语法,另一种使用控制点:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{amssymb}
\usepackage{tikz}
\begin{document}
\begin{center}
\begin{tikzpicture}[
scale=0.4,
mydot/.style={
fill,
circle,
inner sep=1.5pt}
]
\draw[ultra thick] (0,0) circle [radius=2];
\draw [thick,domain=0:60] plot ({2*cos(\x)}, {2*sin(\x)});
\draw [ultra thick,color=red,domain=0:60] plot ({2.1*cos(\x)}, {2.1*sin(\x)});
\draw[thick,dashed,latex-latex]
(-4,0)--(4,0);
\draw[thick,dashed,latex-latex]
(0,-4)--(0,4);
\draw[ultra thick]
(-8,-8)--(-5,6);
\draw[red,thick,dashed,-latex,shorten >= 3pt]
(-5.4,4) to[out=10,in=90,looseness=2] (1,1.7);
\draw[green,thick,dashed,-latex,shorten >= 3pt]
(-5.4,4) to[out=20,in=90] (3,4) to[out=-90,in=45] (1,1.7);
\draw[blue,thick,dashed,-latex,shorten >= 3pt]
(-5.4,4) .. controls (6,7) and (4,5) .. (1,1.7);
\draw[thick] (0,0)--(1,1.7);
\node[mydot,label={left:$\mathbf{0}$}] at (-6.3,0) {};
\node[mydot,label={left:$\mathbf{x}$}] at (-5.4,4) {};
\node at (2.2,1.6) {$x_{o}$};
\node at (0,7) {$\mathbb{R}^{2}$};
\node at (-4.8,7) {$\mathbb{R}$};
\end{tikzpicture}
\end{center}
\end{document}
如果您希望箭头位于路径的中间,那么使用装饰:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\begin{document}
\begin{center}
\begin{tikzpicture}[
scale=0.4,
mydot/.style={
fill,
circle,
inner sep=1.5pt},
decoration={
markings,
mark=at position 0.5 with {\arrow{latex}}
}
]
\draw[ultra thick] (0,0) circle [radius=2];
\draw [ultra thick,color=red,domain=0:60] plot ({2.1*cos(\x)}, {2.1*sin(\x)});
\draw[thick,dashed,latex-latex]
(-4,0)--(4,0);
\draw[thick,dashed,latex-latex]
(0,-4)--(0,4);
\draw[ultra thick]
(-8,-8)--(-5,6);
%\draw[red,thick,dashed,postaction={decorate},shorten >= 3pt]
%(-5.4,4) to[out=10,in=90,looseness=2] (1,1.7);
%\draw[green,thick,dashed,postaction={decorate},shorten >= 3pt]
%(-5.4,4) to[out=20,in=90] (3,4) to[out=-90,in=45] (1,1.7);
\draw[blue,thick,dashed,postaction={decorate},shorten >= 3pt]
(-5.4,4) .. controls (6,7) and (4,5) .. (1,1.7);
\draw[thick] (0,0)--(1,1.7);
\node[mydot,label={left:$\mathbf{0}$}] at (-6.3,0) {};
\node[mydot,label={left:$\mathbf{x}$}] at (-5.4,4) {};
\node at (2.2,1.6) {$x_{o}$};
\node at (0,7) {$\mathbb{R}^{2}$};
\node at (-4.8,7) {$\mathbb{R}$};
\end{tikzpicture}
\end{center}
\end{document}
我还对您的代码做了一些其他修改;主要是使用适当的箭头提示,为填充点定义样式,以及使用选项label
放置\node
一些标签。