# How to draw the dotted part?

I want to make the figure, but I can't do the dotted part outside the circle.

My codes are as follows:

\begin{center}

\begin{tikzpicture}[scale=2.5]

\draw [line width=.08cm,blue,-Stealth] (-1.5,0)--(1.8,0);

\draw [line width=.08cm,blue,-Stealth] (0,-1.5)--(0,1.8);

\node at (1.6,-.2){$\pmb{X}$};

\node at (.2,1.6){$\pmb{Y}$};

\node at (.1,-.1){$\pmb{O}$};

\node at (1.4,.1){$\pmb{A=(1,0)}$};

\node at (60:1.2){$\pmb{P}$};

\node[blue] at (60:1){$\bullet$};

\node[blue] at (0:1){$\bullet$};

\node[blue] at (0,0){$\bullet$};

\draw (0,0)--(60:1);

\draw[line width=.08cm,blue,-Stealth] (1,0)--(0:1cm) arc (0:60:1cm);

\draw[-Stealth] (.3,0)--(0:.3cm) arc (0:60:.3cm);

\node at (.4,.2){$\pmb{\frac{\pi}{3}rd}$};

\end{tikzpicture}

\end{center}

• Please don't post just code fragments. Always make a small, but compilable test file including the necessary packages etc. Commented Jun 13, 2023 at 12:32
• What is the dotted part? Is it a spiral? Does it need to be a spiral? Can it just be semicircles with increasing radii? Commented Jun 13, 2023 at 13:00
• These answer tex.stackexchange.com/questions/623371/… can help? Commented Jun 13, 2023 at 17:22

The spiral can be plotted pretty good by providing points every 10° until 780° (which are 2×360° + 60°). The base radius is 1.1 and for each full revolution the radius gains 0.1.

The arrow is specified with a sep = 2pt where 2pt is the radius of the dot we will place at the same point.

## Code

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows.meta, quotes}
\tikzset{label quotes in math-mode/.style={every label quotes/.append style={execute at begin node=$, execute at end node=$}}}
\begin{document}
\begin{tikzpicture}[
>=Stealth, thick,
dot/.style={shape=circle, inner sep=+0pt, outer sep=+0pt, minimum size=+4pt, fill},
label quotes in math-mode, x=2.5cm, y=2.5cm]
\path[at end, ->, below left]
(left:1.5) edge node {$x$} (right:1.5)
(down:1.5) edge node {$y$} (   up:1.5);

\node[dot, "O"         below left] (O)          {};
\node[dot, "{A=(1,0)}" below left] (A) at (1,0) {};

\draw[draw=red, dashed, -{>[sep=+2pt]}] % sep is half the size of dot
plot[samples at={0,10,...,780}, smooth] (\x:1.1+\x/360*.1)
node[dot, "P" above](P) {};
\draw (O) -- (P);
\end{tikzpicture}
\end{document}