# TikZ - how to draw ticks on circle perpendicularly with ellipses around?

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tikz}

\begin{document}

\begin{figure}
\begin{tikzpicture}
% Draw the line
\draw (0,0) -- (6,0);

% Draw the number 1 at the beginning
\draw (0,-0.1) -- (0,0.1) node[above] {1};

% Draw the number 2
\draw (1,-0.1) -- (1,0.1) node[above] {2};

% Draw ellipses
\node at (3,0.1) {$\dots$};

% Draw the point N at the right end
\draw (6,-0.1) -- (6,0.1) node[above] {N};

% Draw arrow connecting the diagrams
\draw[->] (7.25,0) -- (7.75,0);

% Draw a circle to the right of the number line with numbers
\draw (11, 0) circle (1.5);

% Define the positions for the numbers
\coordinate (1) at (11, 1.5); % Top
\coordinate (2) at (12, 1.118); % Slightly to the right
\coordinate (N) at (10, 1.118); % Slightly to the left

% Draw the ticks on the circle
\draw (11, 1.5-0.1) -- (11, 1.5+0.1) node[above] {1};
\draw (12, 1.118-0.1) -- (12, 1.118+0.1) node[above] {2};
\draw (10, 1.118-0.1) -- (10, 1.118+0.1) node[above] {N};

\end{tikzpicture}
\end{figure}

\end{document}


How do I make sure that the ticks intersect the circle perpendicularly? I also want to add the red dots that go around the circle as indicated in the image.

I use \foreach to place the nodes in polar coordinates.

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}

\begin{figure}
\begin{tikzpicture}
% Draw the line
\draw (0,0) -- (6,0);

% Draw the number 1 at the beginning
\draw (0,-0.1) -- (0,0.1) node[above] {1};

% Draw the number 2
\draw (1,-0.1) -- (1,0.1) node[above] (n2) {2};

% Draw the point N at the right end
\draw (6,-0.1) -- (6,0.1) node[above] (nN) {N};

% Draw ellipses
\node at ($(n2)!.5!(nN)$) {$\dots$};

% Draw arrow connecting the diagrams
\draw[->] (7.25,0) -- (7.75,0);

% Draw a circle to the right of the number line with numbers
\coordinate (O) at (11,0);
\draw (11, 0) circle (1.5);

\foreach \x/\xtext in {45/2,90/1,135/N}
{\draw ($(O)+(\x:1.4)$) --++(\x:.2) node [pos=2] {\xtext};}

\pgfmathsetmacro{\dist}{10}
\foreach \x in {0,160}
{
\node [red] at ($(O)+(\x:1.7)$) {\textbullet};
\node [red] at ($(O)+(\x+\dist:1.7)$) {\textbullet};
\node [red] at ($(O)+(\x+2*\dist:1.7)$) {\textbullet};
}

\end{tikzpicture}
\end{figure}
\end{document}


The idea is to use polar corrdinates. You can play with the angles as per your liking. Here is the complete solution:

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tikz}

\begin{document}

\begin{figure}
\begin{tikzpicture}
% Draw the line
\draw (0,0) -- (6,0);

% Draw the number 1 at the beginning
\draw (0,-0.1) -- (0,0.1) node[above] {1};

% Draw the number 2
\draw (1,-0.1) -- (1,0.1) node[above] {2};

% Draw ellipses
\node at (3,0.1) {$\dots$};

% Draw the point N at the right end
\draw (6,-0.1) -- (6,0.1) node[above] {N};

% Draw arrow connecting the diagrams
\draw[->] (7.25,0) -- (7.75,0);

% Draw a circle to the right of the number line with numbers
\begin{scope}[shift={(11,0)}]
\draw (0, 0) circle (\R);

\node [rotate={60-90}] at (60:\R) {$|$};
\node [above] at (60:\R+0.2) {2};
\node at (90:\R) {$|$};
\node [above] at (90:\R+0.2) {1};
\node [rotate={120-90}] at (120:\R) {$|$};
\node [above] at (120:\R+0.2) {N};

\node [circle,fill=red,inner sep=1pt] at (20:\R+0.2) {~};
\node [circle,fill=red,inner sep=1pt] at (30:\R+0.2) {~};
\node [circle,fill=red,inner sep=1pt] at (40:\R+0.2) {~};
\node [circle,fill=red,inner sep=1pt] at (180-20:\R+0.2) {~};
\node [circle,fill=red,inner sep=1pt] at (180-30:\R+0.2) {~};
\node [circle,fill=red,inner sep=1pt] at (180-40:\R+0.2) {~};
\end{scope}

\end{tikzpicture}
\end{figure}

\end{document}

• It would be nice if you would post compilable examples so people can reuse them more easily. Commented Jun 11 at 10:34