Drawing arrows on the curves lines (transition diagram)

Question

I am trying to replicate the transition diagram below:

So far, I have managed draw all lines and labelled my nodes with the codes below:

\documentclass[]{article}
\usepackage[margin=0.5in]{geometry}
\usepackage{pgfplots}
\renewcommand{\thesection}{\arabic{section}}
\usepackage{mathtools}
\usepackage{cancel}
\usepackage{pgfplots}
\usepackage{amsmath}
\newtheorem{theorem}{THEOREM}
\newtheorem{proof}{PROOF}
\usepackage{tikz}
\usepackage{amssymb}
\usetikzlibrary{patterns}
\usepackage{fancyhdr}
\usepackage{bigints}
\usepackage{color}
\usepackage{tcolorbox}
\usepackage{color,xcolor}
\usepackage{booktabs,array}
\usepackage{hyperref}
\usepackage{graphicx}
\usetikzlibrary{arrows}
\usepackage{polynom}
\usepackage{flexisym}
\usepackage{wallpaper}
\usepackage{blkarray}
\usepackage{caption}
\usepackage{booktabs, makecell, multirow}
\usepackage{stackengine,graphicx,xcolor}
\usepackage{lscape}
\usetikzlibrary{arrows}
\usepackage{flexisym}
\usetikzlibrary{shapes.geometric}
\newenvironment{tightcenter}{
\setlength\topsep{0pt}
\setlength\parskip{0pt}
\begin{center}}{\end{center}}
\begin{document}

\begin{tikzpicture}
\begin{scope}[a/.style = {insert new path = {-triangle 90}}]
%\draw[thick] (0,0) --+ (1,3) --+ (5,3) --+ (4,0) --+ (0,0);
%\draw[thick] (0,0) --+ (1,1.73) --+ (3,1.73) --+ (4,0)--+ (3,-1.73)--+ (1,-1.73)--+ (0,0);
%
\draw[thick,fill=black] (0,0) circle (1.5mm);
\draw[thick,fill=black] (5,0) circle (1.5mm);
\draw[thick,fill=black] (2.5,-3.5) circle (1.5mm);
%
\node [left] at (-0.15, 0.2) {$C$};
\node [right] at (5.2,0.2) {$S$};
\node [below] at (2.5,-3.7) {$T$};
%\node [right] at (4, 0) {$X$};
%\node [below] at (3, -1.73) {$Y$};
%\node [below] at (1, -1.73) {$Z$};
%
\draw[thick](-0.6,0.5) circle (0.8cm);
\draw[thick](0,0) to [bend right=20](5,0);
\draw[thick](0,0) to [bend left=20](5,0);
%
\draw[thick](5.6,0.5) circle (0.8cm);
\draw[thick](0,0) to [bend right=20](2.5,-3.5);
\draw[thick](0,0) to [bend left=20](2.5,-3.5);
%
\draw[thick](2.5,-4.27) circle (0.8cm);
\draw[thick](5,0) to [bend right=20](2.5,-3.5);
\draw[thick](5,0) to [bend left=20](2.5,-3.5);
%
%\draw[thick,opacity=0.7,fill=black] (2.5,1.5) circle (0.5mm);
%\node[above] at (2.5,1.65) {$M$};
\end{scope}
\end{tikzpicture}
\end{document}

I get the following output:

Could anyone experienced please tell me how I can insert these arrows on the curves?

Thank you.

https://tex.stackexchange.com/questions/39278/tikz-arrowheads-in-the-center — current_user, Aug 08 '18 at 15:22

current_user · Answer 1 · 2018-08-08T15:51:14.363

Definitely not the best answer, but it works:

\documentclass[border=5pt,tikz]{standalone}
\usetikzlibrary{arrows,decorations.markings}
%%% https://tex.stackexchange.com/questions/39278/tikz-arrowheads-in-the-center
\tikzset{->-/.style={decoration={
            markings,
            mark=at position #1 with {\arrow{>}}},postaction={decorate}}}
%%%
\begin{document}
    \begin{tikzpicture}[>=triangle 60]
        \begin{scope}[a/.style = {insert new path = {-triangle 90}}]
                \draw[thick,fill=black] (0,0) circle (1.5mm);
                \draw[thick,fill=black] (5,0) circle (1.5mm);
                \draw[thick,fill=black] (2.5,-3.5) circle (1.5mm);
                    \node [left] at (-0.15, 0.2) {$C$};
                    \node [right] at (5.2,0.2) {$S$};
                    \node [below] at (2.5,-3.7) {$T$};
                \draw[->-=.5,thick](.2,0.5) arc(0:-360:.8cm);
                \draw[->-=.5,thick](5,0) to [bend left=20](0,0);
                \draw[->-=.5,thick](0,0) to [bend left=20](5,0);
                \draw[xshift=11.25cm,xscale=-1,->-=.5,thick](5.6,0.5) circle (0.8cm);
                    \draw[->-=.5,thick](2.5,-3.5) to [bend left=20](0,0);
                    \draw[->-=.5,thick](0,0) to [bend left=20](2.5,-3.5);
                    \draw[yscale=-1,yshift=8.55cm,->-=.5,thick](2.5,-4.27) circle (0.8cm);
                    \draw[->-=.5,thick](2.5,-3.5) to [bend left=20](5,0);
                \draw[->-=.5,thick](5,0) to [bend left=20](2.5,-3.5);
        \end{scope}
    \end{tikzpicture}
\end{document}

Here is the output:

EDIT: Just replace some [… ->-=.5 …] with [… ->-=.55 …] to get the arrow heads on the “exact place“ (the whole arrowhead is merging with the one below).

J Leon V. · Accepted Answer · 2018-08-09T04:45:35.470

Better arrow orientation in curves can be done using decorations.markings, which allows you to insert any drawing along a path; then I simplified your code using all the options available by command.

RESULT:

MWE:

\documentclass[border=10pt,tikz]{standalone}
\usetikzlibrary{decorations.markings}

\begin{document}

\begin{tikzpicture}[
    %Environment config
    %Environment Styles
    Circ/.style={circle, fill, minimum width=12pt},
    MidArrow/.style={
        draw,thick, postaction={decorate,decoration={markings,mark=at position 0.5 with {\fill(0:5pt) -- (120:5pt) -- (240:5pt);}}}}
    ]

    %Drawing the nodes
    %\node[tikzstyle, label=angle_orientation:Text](Node_coordinate_Identifier) at (position_in_polar_coordinates){Text_none};
    \node[Circ, label=30:$S$](S) at (30:2.5){};
    \node[Circ, label=150:$P$](P) at (150:2.5){};
    \node[Circ, label=270:$T$](T) at (270:2.5){};

    %Drawing the arrows
    \draw[MidArrow] (P) to [bend left=20] node[anchor=-90, inner sep=8pt]{40\%} (S);
    \draw[MidArrow] (S) to [bend left=20] node[anchor=-90, inner sep=6pt]{20\%} (P);
    \draw[MidArrow] (P) to [bend left=20] node[anchor=50, inner sep=4pt]{20\%} (T);
    \draw[MidArrow] (T) to [bend left=20] node[anchor=30, inner sep=4pt]{20\%} (P);
    \draw[MidArrow] (T) to [bend left=20] node[anchor=-60, inner sep=8pt]{20\%} (S);
    \draw[MidArrow] (S) to [bend left=20] node[anchor=180, inner sep=6pt]{20\%} (T);
    \draw[MidArrow] (P) arc (150-180:150-180-360:0.8) node [midway, anchor=150-180,inner sep=4pt]{40\%};
    \draw[MidArrow] (S) arc (30-180:30-180-360:0.8) node [midway, anchor=30-180,inner sep=4pt]{60\%};
    \draw[MidArrow] (T) arc (270-180:270-180-360:0.8)node [midway, anchor=270-180,inner sep=6pt]{60\%};

    \end{tikzpicture}
\end{document}

UPDATE:

Adding the possibility to control the arrow head position in the curves; then control the label position using the option pos={0_to_1_value} instead midway that is equivalent to pos=0.5, and \sf to get serif font for percent symbol to reproduce a result more similar to the example,demonstrating the great flexibility provided by basic tikz commands.

RESULT:

MWE:

\documentclass[border=10pt,tikz]{standalone}
\usetikzlibrary{decorations.markings}

\begin{document}

\begin{tikzpicture}[
    %Environment config
    %Environment Styles
    Circ/.style={circle, fill, minimum width=12pt},
    InLineArrow/.style={
        draw,thick, postaction={decorate,decoration={markings,mark=at position #1 with {\fill(0:5pt) -- (120:5pt) -- (240:5pt);}}}}
    ]

    %Drawing the nodes
    %\node[tikzstyle, label=angle_orientation:Text](Node_coordinate_Identifier) at (position_in_polar_coordinates){Text_none};
    \node[Circ, label=30:$S$](S) at (30:2.5){};
    \node[Circ, label=150:$P$](P) at (150:2.5){};
    \node[Circ, label=270:$T$](T) at (270:2.5){};

    %Drawing the arrows
    \draw[InLineArrow=0.5] (P) to [bend left=20] node[anchor=-90, inner sep=8pt]{40\sf\%} (S);
    \draw[InLineArrow=0.5] (S) to [bend left=20] node[anchor=-90, inner sep=6pt]{20\sf\%} (P);
    \draw[InLineArrow=0.5] (P) to [bend left=20] node[anchor=50, inner sep=4pt]{20\sf\%} (T);
    \draw[InLineArrow=0.5] (T) to [bend left=20] node[anchor=30, inner sep=4pt]{20\sf\%} (P);
    \draw[InLineArrow=0.5] (T) to [bend left=20] node[anchor=-60, inner sep=8pt]{20\sf\%} (S);
    \draw[InLineArrow=0.5] (S) to [bend left=20] node[anchor=180, inner sep=6pt]{20\sf\%} (T);
    \draw[InLineArrow=0.41] (P) arc (150-180:150-180-360:0.8) node [pos=0.41, anchor=180-180,inner sep=7pt]{40\sf\%};
    \draw[InLineArrow=0.58] (S) arc (30-180:30-180-360:0.8) node [pos=0.58, anchor=0-180,inner sep=7pt]{60\sf\%};
    \draw[InLineArrow=0.75] (T) arc (270-180:270-180-360:0.8)node [pos=0.65, anchor=180-180,inner sep=7pt]{60\sf\%};

    \end{tikzpicture}
\end{document}

They are tangent to the circle from the barycenter, not from the tip as in your MWE, which causes the base to be very out of phase with the arrow line. — J Leon V., Aug 08 '18 at 19:58

score 5 · Answer 3 · 2018-08-09T02:40:29.960

After imgur recovered I could see the desired output. I'd like to argue that the arrows become slightly nicer

when the arrows get bent
one uses symbolic coordinates that are arranged more symmetically
and allows for arbitrary positions.

Otherwise this post has substantial overlap with the other great answers.

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{decorations.markings,arrows.meta,bending}
\begin{document}
% inspired by https://tex.stackexchange.com/a/316050/121799
% and further developed in https://tex.stackexchange.com/a/430239/121799
\tikzset{
    arc arrow/.style args={%
    to pos #1 and length #2 and label #3}{
    decoration={
        markings,
         mark=at position 0 with {\pgfextra{%
         \pgfmathsetmacro{\tmpArrowTime}{#2/(\pgfdecoratedpathlength)}
         \xdef\tmpArrowTime{\tmpArrowTime}}},
        mark=at position {#1-\tmpArrowTime} with {\coordinate(@1);},
        mark=at position {#1-2*\tmpArrowTime/3} with {\coordinate(@2);},
        mark=at position {#1-\tmpArrowTime/3} with {\coordinate(@3);},
        mark=at position {#1} with {\coordinate(@4);
        \draw[-{Triangle[bend,length=#2]}]       
        (@1) .. controls (@2) and (@3) .. (@4)
        node[pos=0.8,auto,font=\sffamily]{#3};},
        },
     postaction=decorate,
     }
}

\begin{tikzpicture}
\begin{scope}[thick]
%
\draw[fill=black] (150:3.5) coordinate[label={[above left=2pt]P}] (P) circle (1.5mm);
\draw[fill=black] (30:3.5) coordinate[label={[above right=2pt]S}] (S) circle (1.5mm);
\draw[fill=black] (-90:3.5) coordinate[label={[below=2pt]T}] (T) circle (1.5mm);
%
\draw[arc arrow=to pos 0.45 and length 3mm and label {40\,\%}](P) arc(-30:-390:0.8cm);
\draw[arc arrow=to pos 0.5 and length 3mm and label {20\,\%}](P) to [bend left=20] (T);
\draw[arc arrow=to pos 0.5 and length 3mm and label {20\,\%}](T) to [bend left=20] (P);
%
\draw[arc arrow=to pos 0.65 and length 3mm and label {60\,\%}](S) arc(210:-150:0.8cm);
\draw[arc arrow=to pos 0.5 and length 3mm and label {20\,\%}](S) to [bend left=20] (P);
\draw[arc arrow=to pos 0.5 and length 3mm and label {40\,\%}](P) to [bend left=20] (S);
%
\draw[arc arrow=to pos 0.7 and length 3mm and label {60\,\%}](T) arc(90:-270:0.8cm);
\draw[arc arrow=to pos 0.5 and length 3mm and label {20\,\%}](T) to [bend left=20] (S);
\draw[arc arrow=to pos 0.5 and length 3mm and label {20\,\%}](S) to [bend left=20] (T);
%
\end{scope}
\end{tikzpicture}
\end{document}

This is really good. But do you think you can make the arrows be in triangular shape? — Will Kim, Aug 08 '18 at 15:40
@Will_Kim: just ad \begin{tikzpicture][>=triangle 60] …; see also my answer, but marmot's answer is better … — current_user, Aug 08 '18 at 15:43
@WillKim Just replace Stealth[] by Triangle[]. If you want to reverse it, use Triangle[reversed]. The full set of options for the Triangle arrow is described on p. 210 of the pgfmanual. (current_user: Thanks!) — , Aug 08 '18 at 15:47

score 5 · Answer 4 · answered Aug 08 '18 at 15:51

One can define an arrow style in Tikz. I used the idea from this answer.

Put \usetikzlibrary{decorations.markings} in the preamble and write the following code right below \begin{document}

\tikzset{middlearrow/.style={
        decoration={markings,
            mark= at position 0.5 with {\arrow{#1}} ,
        },
        postaction={decorate}
    }
}

And then, write the parameter middlearrow={'type of arrow here'}. I used stealth reversed.

Drawing arrows on the curves lines (transition diagram)

4 Answers4

UPDATE: