Labelling edges drawn by the draw to command

Question

consider the following code:

\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
  },
  transition/.style={
    rectangle,
    thick,
    fill=black,
    minimum width=8mm,
    inner ysep=2pt
    }
  }            

\begin{document}

\begin{tikzpicture}[node distance=1.3cm,>=stealth',bend angle=45,auto]
    \node [place] (C) []     {C};
    \node [transition] (t4) [below left of=C,label=right:$t4$]     {};
    \node [place] (E) [below right of=t4]     {E};
    \draw [<-] (E.west) to [out=180,in=270] (t4);
    \draw [<-] (C.west) to [out=180,in=90] (t4);
\end{tikzpicture}

\end{document}

I would like to add a label to the two edges I created with the draw command. I know that there have already been some questions on this site regarding the labelling of edges in Tikz (eg, here and here) but these all use a different syntax for the draw command. I know I have to create an extra node in my draw command but unfortunately I failed to find the right the position for this within the draw command and I keep getting errors.

By the way, I am somewhat confused by the multiple syntactic variants of the draw command. Is there a good overview of its usage somewhere?

Thanks for your help!

Answer 1

May be this is what you want:

\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
  },
  transition/.style={
    rectangle,
    thick,
    fill=black,
    minimum width=8mm,
    inner ysep=2pt
    }
  }

\begin{document}

\begin{tikzpicture}[node distance=1.3cm,>=stealth',bend angle=45,auto]
    \node [place] (C) []     {C};
    \node [transition] (t4) [below left of=C,label=right:$t4$]     {};
    \node [place] (E) [below right of=t4]     {E};
    \draw [<-] (E.west) to[out=180,in=270]node[pos=0.5,left]{here} (t4) ;
    \draw [<-] (C.west) to[out=180,in=90]node[pos=0.5,left]{here}  (t4);
\end{tikzpicture}

\end{document}

Adjust the pos key suitably and use left/right/above/below as you need.

The best source for these commands is the pgfmanual itself, IMO.