Graphics, Figures & Tables ⇒ tikZ | Nodes midway on connecting Arrows

[gheorghebg]

Hello.

I am using tikz to draw commutative diagrams in mathematics. I would like to draw a diagram as in the .png attached. I almost reproduced it with the following code

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\begin{center}
\begin{tikzpicture}
\matrix (m) [matrix of math nodes, row sep=7em, column sep=10em, text height=1.5ex, text depth=0.5ex]
{ \catC & \UC    & \UC / S\\
        & \catM.      \\ };
\path[right hook->]
(m-1-1) edge node[above] {$r$} (m-1-2);
\path[->]
(m-1-1) edge node[below=3pt, left = 3pt] {$\gamma$} (m-2-2)
(m-1-2.20) edge node[above] {$\id$} (m-1-3.166)
(m-1-3.184) edge node[below] {$\id$} (m-1-2.354)

(m-1-2.248) edge node[left] {$Re$} (m-2-2.112)
(m-2-2.68) edge node[right] {$Sing$} (m-1-2.292);
\path[->, dotted] 
(m-2-2.0) edge node[above =10pt, left = 3pt] {$ Sing $} (m-1-3.275)
(m-1-3.217) edge node[below = 9pt, right = 4pt] {$ Re $} (m-2-2.34);
\end{tikzpicture}
\end{center}

I am just missing the red symbols. How could I add them to the picture ?
Thanks for your help. Bogdan

[Stefan Kottwitz]

Hi Bogdan,

welcome to the board!

You could add a node to the edge, such as

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(m-2-2.68) edge node[right] {$Sing$} node [left] {$\dashv$} (m-1-2.292);

Furthermore, I would not write $Sing$, as this would be italic just like a product of 4 variables, with a math symbol spacing. I would use a roman font.

Btw. when you post code to the forum, which is very good, please also include the required macro definitions, otherwise we cannot really test. The best in any way is a minimal working example.

Stefan

[gheorghebg]

Hi Stefan, Thanks. I'm embarrassed I didn't thought of it . For the $Sing$, it is indeed the result I want in math mode.

Thank you for you fast answer !
Bogdan