[Tex/LaTex] Controlling edge shape in tikz

automatatikz-pgf

I have written latex code for automata using tikz.
I am using \path and \draw for my edges (cf figure1), and I want to have edges of the form (cf figure 2). Any thoughts on how to do it?

Thanks in advance

EDIT: Here is my code:

\documentclass{article}
\usepackage[demo]{graphicx}
\usepackage{caption}
\usepackage{subcaption}
% Packages
\usepackage{fixltx2e}
\usepackage{ntheorem}
\usepackage{float}
\usepackage{xr}
\usepackage{geometry}
\usepackage{algpseudocode}
\usepackage{algorithmicx}
\usepackage{algorithm}
\usepackage{caption}
\usepackage{pifont}
\usepackage{verbatim}
\usepackage[english]{babel}
\usepackage{wrapfig}
\usepackage{capt-of}
\usepackage{color}
\usepackage{pdftricks}
\usepackage{etex}
\usepackage[version=0.96]{pgf}
\usepackage{tikz}
\usetikzlibrary {plotmarks,calc,arrows,shapes,snakes,automata,backgrounds,petri,positioning,fit}
\usepackage{proof}
\usepackage{latexsym}
\usepackage{amsfonts}
\usepackage{stackrel}
\usepackage{amsmath}
%\usepackage{amssymb}
%\usepackage{amsthm}
\usepackage{subcaption}

\begin{document}
\begin{figure}[H]
  \centering
\begin{tikzpicture}[->,node distance=1.3cm,>=stealth',bend angle=40,auto,
  place/.style={circle,thick,draw=blue!75,fill=blue!20,minimum size=10mm},
  red place/.style={place,draw=red!75,fill=red!20}
  every label/.style={red},
  every node/.style={scale=.6},
  dots/.style={fill=black,circle,inner sep=2pt},
  initial text={}]

  \node [accepting, place,label={[shift={(0.4,-1.9)}]$x\le850$}] (l1-1)  {$l_1^1$};
  \node [place,right=2cm of l1-1] (l1-2) {$l_2^1$};

  \path (l1-1) edge [in=160,out=190,loop,align=center] node[left]{vp\\$x:=0$} (l1-1)
           edge [in=240,out=210,loop,align=center] node[below,xshift=-7mm]{vs\\
           $x < 850$\\$x:=0$} (l1-1)
           edge [in=140, out=110,loop,align=center] node[above]{ap\\$x \ge 850$
           \\$x:=0$} (l1-1)
    (l1-1) edge node[above]{ats} (l1-2)
    (l1-2) edge [bend right] node[above,align=center]{vp, $x:=0$} (l1-1)
    edge [bend left] node[below,align=center]{vs, $x:=0$} (l1-1);

  \node [accepting, place,right=2cm of l1-2,yshift=1.5cm] (l2-1)  {$l_1^2$};
  \node [place,right=2cm of l2-1,label={[shift={(1.4,-0.9)}]$y\le150$}] (l2-2) {$l_2^2$};
  \node [place,below=2cm of l2-2,label={[shift={(1.4,-0.9)}]$k\le400$}] (l2-3) {$l_3^2$};

  \draw (l2-1) to[in=100,out=90] node[above,align=center] {ats, $y:=0$} (l2-2) ;
  \draw (l2-1) to[in=150,out=40] node[above,align=center] {ap, $y:=0$} (l2-2) ;
  \draw (l2-2) to[in=-20,out=-150] node[below,align=center] {ats, $k:=0$} (l2-1) ;
  \draw (l2-2) to[in=-60,out=-110] node[below,align=center] 
    {ap, $k:=0$\\$y\ge150 \text{ \& } k\ge400$} (l2-1) ;
  \draw [->](l2-2)-- node[right,align=center] {internalp\\ $y\ge150 \text{ \& } k\le400$} (l2-3) ;
  \draw (l2-3) to[in=-90,out=-180] node[above,align=center,xshift=9mm,yshift=-3mm] {vs, $k:=0$}
        (l2-1) ;
  \draw (l2-3) to[in=-110,out=-150] node[below,align=center,xshift=-13mm,yshift=5mm] 
       {vp, $k:=0$\\$k>400$} (l2-1) ;

  \node [accepting, place,below=4cm of l1-1, xshift=-15mm] (l3-1)  {$l_1^3$};
  \node [place,right=1.5cm of l3-1,label={[shift={(0,-1.9)}]$y\le50$}] (l3-2) {$l_2^3$};
  \node [place,right=1.5cm of l3-2,label={[shift={(1.4,-0.9)}]$k\le100$}] (l3-3) {$l_3^3$};
  \node [place,below=1.5cm of l3-3] (l3-4) {$l_4^3$};
  \node [place,below=1.5cm of l3-1] (l3-5) {$l_5^3$};


  \path (l3-1) edge node[below]{vp, $z:=0$} (l3-2)
           edge [bend left] node[above,align=center]{vp, $z:=0$} (l3-2)
           edge node[right]{aget} (l3-5)
    (l3-5) edge [bend left] node[left]{ats} (l3-1)
    (l3-2) edge node[above]{internalp, $z\ge50$} (l3-3)
    (l3-3) edge node[right]{aget} (l3-4)
    (l3-4) edge[bend left] node[left,align=center]{internalp\\ $z\le100$} (l3-3);
  \draw (l3-3) to[in=90,out=90] node[above,align=center] 
       {internalp\\ $z\ge100$} (l3-1) ;

  \node [accepting, place,right=2cm of l3-3] (l4-1)  {$l_1^4$};
  \node [place,right=1.5cm of l4-1,label={[shift={(1.4,-0.9)}]$y\le150$}] (l4-2) {$l_2^4$};
  \node [place,below=1.5cm of l4-1] (l4-3) {$l_3^4$};

  \path (l4-1) edge node[left]{vget} (l4-3)
           edge node[below,align=center]{vp, $t:=0$} (l4-2)
    (l4-2) edge[bend right] node[above]{internalp, $t\ge150$} (l4-1)
    (l4-3) edge node[below,xshift=5mm]{vs, $t:=0$} (l4-2);
\end{tikzpicture}
\caption{enter1 and enter2 form a false-conflict based on timing constraint}\label{fig:fish}
\end{figure}
\end{document}

Best Answer

Here is an example using rounded corners option with straight lines. I define some styles (sh2n, sh2se, etc.) to shift node's centers.

\documentclass[tikz,margin=5mm]{standalone}
\usetikzlibrary{positioning}
\begin{document}
\begin{tikzpicture}[node distance=2cm and 2cm]
  \tikzset{
    sh2n/.style={shift={(0,1)}},
    sh2s/.style={shift={(0,-1)}},
    sh2e/.style={shift={(1,0)}},
    sh2w/.style={shift={(-1,0)}},
    %
    sh2nw/.style={shift={(-1,1)}},
    sh2ne/.style={shift={(1,1)}},
    sh2sw/.style={shift={(-1,-1)}},
    sh2se/.style={shift={(1,-1)}},
    %
    rc/.style={rounded corners=2mm,line width=1pt},
    %
    place/.style={draw,circle,fill=cyan!10,inner sep=.5mm,minimum size=5mm},
  }
  \node[place] (a) {a};
  \node[place,left=of a] (b) {b};
  \node[place,above right=of a] (c) {c};

  \draw[-stealth,rc] (a) -- node[above]{a to b} (b);
  \draw[-stealth,rc] (a) |- node[green!50!black,above,pos=.75]{a to c} (c);
  \draw[-stealth,rc] (a) -- ([sh2nw]a.center) -- node[above,red] {a to c (bis)} ([sh2n]b.center) -- (b);
  \draw[-stealth,rc] (b) -- ([sh2se]b.center) -| node[below,blue,pos=.25] {b to c} (c);
\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

The source of the difficulty is that ellipses are constructed in a particular way in TikZ. They are paths that start from the x-axis and proceed counter-clockwise around their centre. The vast majority of the time, the exact parametrisation doesn't matter. You appear to have found the one situation where it does!

In the actual question, you only want to be able to mirror the ellipse, and so draw it starting from the negative x-axis (the title of the question suggests a more flexible approach). That's actually not too hard since we can exploit the symmetry of the ellipse. The key is to provide it with a negative x-radius, since then it will start from the negative x-axis (and proceed clockwise, but we could correct for that by negating the y-radius as well). To do this, we interrupt the call from the node shape to the drawing command and flip the sign of the x-radius. The simplest way to do this is to redefine the \pgfpathellipse macro to do the negation and then call the original macro. The following code does this.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations,shapes,decorations.markings}
\makeatletter
\let\origpgfpathellipse=\pgfpathellipse
\def\revpgfpathellipse#1#2#3{%
  #2%
  \pgf@xa=-\pgf@x
  \origpgfpathellipse{#1}{\pgfqpoint{\pgf@xa}{0pt}}{#3}}
\makeatother

\tikzset{
  reversed ellipse/.style={
    ellipse,
    reverse the ellipse%
  },
  reverse the ellipse/.code={
    \let\pgfpathellipse=\revpgfpathellipse
  }
}
\begin{document}
\begin{tikzpicture}
\node[ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,0) {hello world};

\node[reversed ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,-2) {hello world};
\end{tikzpicture}

\end{document}

Here's the result:

rotated ellipse

(the arrow got clipped, but you can see where it lies)

[Tex/LaTex] Draw edge on arc

you say:

drawing an arc alone does not draw arrows and does not end at the "borders" of the nodes, but at there center

(*their center, b.t.w.)

but it is not completely true; you can try with a workaround with arc. For example:

\draw [right, ->] (0.3,8) arc [radius=4, start angle=90, end angle= 0];

will draw an arrow from V1 to almost V2.

Playing around with the radius and the location of the nodes you can draw your circle (with arrows, see the -> above)

EDIT:

to avoid playing around with the starting location you can use node anchors:

\draw [->] (V1.east) arc [radius=4, start angle=90, end angle= 0];

Best Answer

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

[Tex/LaTex] Draw edge on arc

Related Question