Petri 网中的转换

Question

我是 Tikz 的新手，

读完这个问题后Petri 网中的转换

我想创建这个

这是我的代码，您可以通过此链接访问https://www.writelatex.com/read/bxwwcmmghpmw

\documentclass{article}

\usepackage[version=0.96]{pgf}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes,automata,petri}

\tikzset{
    place/.style={
        circle,
        thick,
        draw=blue!75,
        fill=blue!20,
        minimum size=6mm,
    },
    transitionH/.style={
        rectangle,
        thick,
        fill=black,
        minimum width=8mm,
        inner ysep=2pt
    },
    transitionV/.style={
        rectangle,
        thick,
        fill=black,
        minimum height=8mm,
        inner xsep=2pt
    }
}

\begin{document}

\begin{tikzpicture}[node distance=1.3cm,>=stealth',bend angle=45,auto]
    \node [place,label=above:$P_1$] (p1) {};
    \node [transitionV,label=above:$T_1$] (t1) [right of=p1] {}
        edge[pre]   (p1);
    \node [place,tokens=1,label=above:$P_2$] (p2) [right of=t1] {}
        edge[pre]   (t1);
    \node [place,tokens=2,label=above:$P_3$] (p3) [below of=p2] {}
        edge[pre]   (t1);
    \node [transitionV,label=above:$T_2$] (t2) [right of=p3] {}
        edge[pre]   (p2)
        edge[pre]   (p3)
        edge[post, bend left]  (p1);
    \node [place,tokens=1, label=above:$P_4$] (p4) [right of=t2] {}
        edge[pre]   (t2);
\end{tikzpicture}

\end{document}

我对 T2 --> P1 的边缘不太满意，我希望它们垂直居中。

非常感谢您的帮助。

Answer 1

也许是这样的：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes,automata,petri,positioning}

\tikzset{
    place/.style={
        circle,
        thick,
        draw=blue!75,
        fill=blue!20,
        minimum size=6mm,
    },
    transitionH/.style={
        rectangle,
        thick,
        fill=black,
        minimum width=8mm,
        inner ysep=2pt
    },
    transitionV/.style={
        rectangle,
        thick,
        fill=black,
        minimum height=8mm,
        inner xsep=2pt
    }
}

\begin{document}

\begin{tikzpicture}[node distance=0.5cm and 1cm,>=stealth',bend angle=45,auto]
    \node [place,label=above:$P_1$] (p1) {};
    \node [transitionV,label=above:$T_1$] (t1) [right= of p1] {}
        edge[pre]   (p1);
    \node [place,tokens=1,label=above:$P_2$] (p2) [above right=of t1] {}
        edge[pre]   (t1);
    \node [place,tokens=2,label=above:$P_3$] (p3) [below right=of t1] {}
        edge[pre]   (t1);
    \node [transitionV,label=above:$T_2$] (t2) [above right=of p3] {}
        edge[pre]   (p2)
        edge[pre]   (p3)
        edge[post,out=-110,in=-50,looseness=2,overlay]  (p1);
    \node [place,tokens=1, label=above:$P_4$] (p4) [above right=of t2] {}
        edge[pre]   (t2);
\end{tikzpicture}

\end{document}

主要的变化是从过时的语法切换of=到of=（使用positioning库进行相对定位，并使用out=<angle>、in=<angle>和 一起looseness作为边缘（根据您的喜好调整设置）。

另一种选择，这次使用to路径而不是edge：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes,automata,petri,positioning}

\tikzset{
    place/.style={
        circle,
        thick,
        draw=blue!75,
        fill=blue!20,
        minimum size=6mm,
    },
    transitionH/.style={
        rectangle,
        thick,
        fill=black,
        minimum width=8mm,
        inner ysep=2pt
    },
    transitionV/.style={
        rectangle,
        thick,
        fill=black,
        minimum height=8mm,
        inner xsep=2pt
    }
}

\begin{document}

\begin{tikzpicture}[node distance=0.4cm and 1cm,>=stealth',bend angle=45,auto]
    \node [place,label=above:$P_1$] (p1) {};
    \node [transitionV,label=above:$T_1$] (t1) [right= of p1] {}
        edge[pre]   (p1);
    \node [place,tokens=1,label=above:$P_2$] (p2) [above right=of t1] {}
        edge[pre]   (t1);
    \node [place,tokens=2,label=above:$P_3$] (p3) [below right=of t1] {}
        edge[pre]   (t1);
    \node [transitionV,label=above:$T_2$] (t2) [above right=of p3] {}
        edge[pre]   (p2)
        edge[pre]   (p3);
    \node [place,tokens=1, label=above:$P_4$] (p4) [above right=of t2] {}
        edge[pre]   (t2);
   \draw[post] (t2.east)  to[out=-30,in=210,overlay,looseness=2.3]  (p1);     
\end{tikzpicture}

\end{document}