latex - Tikz:从节点绘制边到另一边的标签

Question

我想弄清楚如何在 tikz 中的节点和其他两个节点之间的边缘标签之间绘制一条边。这是我正在尝试做的一个例子:


这是我的代码:

\documentclass[11pt]{article}
\usepackage[margin=1in, top=1.5in]{geometry}
\usepackage{amsmath,amssymb,bbm}
\usepackage{graphicx}
\usepackage{tikz}
\usetikzlibrary{arrows, positioning}

\setlength{\parindent}{0.25in}
\newcommand{\assign}{:=}
\usepackage[hang,small,bf]{caption}


\begin{document}

\begin{figure}[!h]
  \centering
  \begin{tikzpicture}[shorten >=1pt,node distance=3cm,on grid,auto]
    \tikzstyle{state}=[shape=circle,thick,draw,minimum size=1.5cm]

    \node[state] (A1) {$A_1$};
    \node[state,above of=A1] (B1) {$B_1$};
    \node[state,above of=B1] (C1) {$C_1$};

    \node[state,right of=A1] (A2) {$A_2$};
    \node[state,above of=A2] (B2) {$B_2$};
    \node[state,above of=B2] (C2) {$C_2$};



    \path[->,draw,thick]
    (A1) edge node {$l_A$} (B2)
    (B1) edge node {$l_B$} (B2)

    ;

  \end{tikzpicture}
  \caption{Model}
  \label{fig:f1}
\end{figure}


\end{document}

有人可以告诉我如何获得这种效果吗？

谢谢!

Answer 1

根据文档，

You may also add the option name=<name> to the option list; it has the same effect [as providing a node name with (name)]

用你的例子，这给出:

\documentclass[11pt]{article}
\usepackage[margin=1in, top=1.5in]{geometry}
\usepackage{amsmath,amssymb,bbm}
\usepackage{graphicx}
\usepackage{tikz}
\usetikzlibrary{arrows, positioning}

\setlength{\parindent}{0.25in}
\newcommand{\assign}{:=}
\usepackage[hang,small,bf]{caption}


\begin{document}

\begin{figure}[!h]
  \centering
  \begin{tikzpicture}[shorten >=1pt,node distance=3cm,on grid,auto]
    \tikzstyle{state}=[shape=circle,thick,draw,minimum size=1.5cm]

    \node[state] (A1) {$A_1$};
    \node[state,above of=A1] (B1) {$B_1$};
    \node[state,above of=B1] (C1) {$C_1$};

    \node[state,right of=A1] (A2) {$A_2$};
    \node[state,above of=A2] (B2) {$B_2$};
    \node[state,above of=B2] (C2) {$C_2$};



    \path[->,draw,thick]
    (A1) edge node[name=la] {$l_A$} (B2)
    (B1) edge node[name=lb] {$l_B$} (B2)

    ;
    \draw[->, thick, bend left=15]  (C1) edge (la) edge (lb); 

  \end{tikzpicture}
  \caption{Model}
  \label{fig:f1}
\end{figure}


\end{document}

screenshot of output