绘制稳定区域

Question

我想绘制这个图形，这是我的代码和结果。我希望删除我在图中标记的垂直线，并且点 $q pi/2$ 远离圆弧，而不是像原始图形那样粘在圆弧上。。

\begin{tikzpicture}

\draw[fill=gray!10]
(-3,-3) -- (-3,3)  -- (0,0) -- cycle;

\draw[very thick, ->] (-3,0) -- (3,0) node[right] {Re};
\draw[very thick, ->] (0,-3) -- (0,3.5) node[above] {Im};

\draw[very thick, <->] 
(0:1) arc[start angle=0, end angle=135, radius=1] 
node[midway, right] {$q\frac{\pi}{2}$};

\node[align=center] at (2.3,-1) {unstable  region};
\node[align=center] at (-2,-1) {stable  region};

\end{tikzpicture}

Answer 1

• 如果你不想让灰色三角形闭合，那么就不要用-- cycle

• xshift=您可以使用和来移动节点yshift=。或者，您可以增加outer sep=节点的。

---

\documentclass{article}
\usepackage{tikz} 

\begin{document}

\begin{tikzpicture}

\draw[fill=gray!10] (-3,-3)  -- (0,0) -- (-3,3);

\draw[very thick, ->] (-3,0) -- (3,0) node[right] {Re};
\draw[very thick, ->] (0,-3) -- (0,3.5) node[above] {Im};

\draw[very thick, <->] 
(0:1) arc[start angle=0, end angle=135, radius=1] 
node[midway, right,xshift=0.25cm,yshift=0.25cm] {$q\frac{\pi}{2}$};

\node[align=center] at (2.3,-1) {unstable  region};
\node[align=center] at (-2,-1) {stable  region};

\end{tikzpicture}

\end{document}