Btukfyl

I managed to get the two pictures below. I think I'd have to rotate the straight line and connect its end to the number 615 so that it looks like the $rho$ letter. How can I do that? Feel free to suggest a whole different approach.

Notice how the arrows of the straight line are too small compared to the ones in the cycle. I'd also appreciate seeing an approach where these arrow sizes are similar. It's okay if I have to type up each node --- as long defining their position is a sane procedure. I'm sure whatever you come up with will better than I could do today --- having read only the first pages of the TikZ manual.

% A simple cycle

% Author : Jerome Tremblay

documentclass{article}

usepackage{tikz}

begin{document}



begin{tikzpicture}

def n {11}

def radius {3.5cm}

def margin {8} % margin in angles, depends on the radius



%% draw[step=.5cm,gray,very thin] (-7,-7) grid (7,7);

%% draw (0,0) circle (0.1cm);

%% --8<---------------cut here---------------start------------->8---

%% the tail

%% path 

%%  (0,0) node [shape=circle,draw,minimum width=1cm]{$2$}

%%  (1,0) node [shape=circle,draw,minimum width=1cm]{$12$}

%%  (2,0) node [shape=circle,draw,minimum width=1cm]{$152$}

%%  (3,0) node [shape=circle,draw,minimum width=1cm]{$1223$}

%%  (4,0) node [shape=circle,draw,minimum width=1cm]{$1031$}

%%  (5,0) node [shape=circle,draw,minimum width=1cm]{$2916$}

%%  (6,0) node [shape=circle,draw,minimum width=1cm]{$751$}

%%  (7,0) node [shape=circle,draw,minimum width=1cm]{$1149$};





%% --8<---------------cut here---------------end--------------->8---



% the cycle

def s {1}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$456$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {2}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$1562$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {3}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$792$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {4}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$1872$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {5}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$2152$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {6}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$25$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {7}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$441$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {8}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$615$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {9}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$2993$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {10}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$2329$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



def s {11}

node[draw=none] at ({360/n * -(s - 1)}:radius) {$2031$};

draw[<-, >=latex] ({360/n * (s - 1)+margin}:radius) 

   arc ({360/n * (s - 1)+margin}:{360/n * (s)-margin}:radius);



end{tikzpicture}



begin{tikzpicture}[node distance=1.5cm,minimum width=1.2cm]

node(n0) [draw=none] at (-15,0) {$2$};

node (n1) [draw=none,right of=n0]{$12$};

node (n2) [draw=none,right of=n1]{$152$};

node (n3) [draw=none,right of=n2]{$1223$};

node (n4) [draw=none,right of=n3]{$1031$};

node (n5) [draw=none,right of=n4]{$2916$};

node (n6) [draw=none,right of=n5]{$751$};

node (n7) [draw=none,right of=n6]{$1149$};

draw [->] (n0) to (n1);

draw [->] (n1) to (n2);

draw [->] (n2) to (n3);

draw [->] (n3) to (n4);

draw [->] (n4) to (n5);

draw [->] (n5) to (n6);

draw [->] (n6) to (n7);

end{tikzpicture}



end{document}

Your circle and straight lines can be coded much shorter, which also allows you to change the positions of the various nodes very easily.

documentclass[tikz,border=3.14mm]{standalone}

usetikzlibrary{chains,positioning}

begin{document}



begin{tikzpicture}[node distance=1.5cm]

node[circle,minimum width=7cm] (circ) {};

foreach X [count=Y] in {456,1562,792,1872,2152,25,441,615,2993,2329,2031}

{node  (cnY) at ({-(Y-2.5)*360/11}:3.5) {$X$}; }

foreach Y [remember=Y as LastY (initially 11)]in {1,...,11}

{draw[-latex,shorten >=4pt,shorten <=4pt] (cnLastY) to[bend left=10] (cnY);}

begin{scope}[start chain = going below,every node/.append style={on chain},

every join/.style=-latex]]

node[below=of cn8] (n0) {2};

draw[-latex] (cn8) -- (n0);

node[join] (n1) {$12$};

node[join] (n2) {$152$};

node[join] (n3) {$1223$};

node[join] (n4) {$1031$};

node[join] (n5) {$2916$};

node[join] (n6) {$751$};

node[join] (n7) {$1149$};

end{scope}

end{tikzpicture}

end{document}

Just for fun: the straight line of a latex rho has an angle of approximately 76 degrees.

documentclass[tikz,border=3.14mm]{standalone}

begin{document}

begin{tikzpicture}

node[scale=15]{$rho$};

draw[white,thick,double=blue] (-0.5,0.6)  -- (-1.05,-1.6)

node[midway,left=5mm,scale=3,blue]{pgfmathparse{atan2(0.6+1.6,1.05-0.5)}%

$pgfmathprintnumber{pgfmathresult}^circ$};

end{tikzpicture}

end{document}

This raises the question if one can make the chain such that it has this angle. The answer is yes.

documentclass[tikz,border=3.14mm]{standalone}

usetikzlibrary{chains,positioning}

begin{document}



begin{tikzpicture}[node distance=1.5cm]

node[circle,minimum width=7cm] (circ) {};

foreach X [count=Y] in {456,1562,792,1872,2152,25,441,615,2993,2329,2031}

{node  (cnY) at ({-(Y-2.5)*360/11}:3.5) {$X$}; }

foreach Y [remember=Y as LastY (initially 11)]in {1,...,11}

{draw[-latex,shorten >=4pt,shorten <=4pt] (cnLastY) to[bend left=10] (cnY);}

begin{scope}[start chain = going below,every node/.append style={on chain,

,xshift=-{cot(76)*1.5cm}},

every join/.style=-latex]

node[below=of cn8] (n0) {2};

draw[-latex] (cn8) -- (n0);

node[join] (n1) {$12$};

node[join] (n2) {$152$};

node[join] (n3) {$1223$};

node[join] (n4) {$1031$};

node[join] (n5) {$2916$};

node[join] (n6) {$751$};

node[join] (n7) {$1149$};

end{scope}

end{tikzpicture}

end{document}

this is not really answer (for it i was to late for one minute), just an illustration to @marmot how i imagine rho "tail" to circle ...

documentclass[tikz, margin=3mm]{standalone}

usetikzlibrary{chains, positioning}



begin{document}



begin{tikzpicture}[

node distance = 4mm and 6mm,

  start chain = going below left,

   box/.style = {minimum width=5ex, inner xsep=0pt,

                 on chain, join=by latex-}

                    ]

def n {11}

def radius {3.5cm}

def margin {8} % margin in angles, depends on the radius

% the cycle

foreach s [count=i from 0,

             count=j from 1] in {456, 1562, 792, 1872, 2152,

                                  25,  441,  615, 2993, 2329, 2031}

{

node (sj)  at (-i*360/n:radius) {$s$};

draw[latex-] (i*360/n + margin:radius)

                arc (i*360/n +margin:j*360/n -margin:radius);

}

node (d1) [box, below left=of s8] {$2$};

node[box]   {$12$};

node[box]   {$152$};

node[box]   {$1223$};

node[box]   {$1031$};

node[box]   {$2916$};

node[box]   {$751$};

node[box]   {$1149$};

draw[red,-latex]  (d1) -- (s8);

end{tikzpicture}



end{document}

as all can see, difference between codes can be neglected ... slope of line can be adjusted with node distance. for example, i would rather start at node on circle with "441" and make slope more stepped:

node distance = 5mm and -2.5ex,

and star with tail:

node (d1) [box, below left=of s7] {$2$};

for red arrows i was not sure, if it s desired (so it is red)