Fine-tuning a commutative diagram

Question

I am trying to type the following simple commutative diagram in LaTeX. I have the basics, but I need for the V to be centered, and for the arrow under the g to be in the opposite direction.

\begin{tikzpicture}[every node/.style={midway}]
\matrix[column sep={4em,between origins},
    row sep={2em}] at (0,0)
{ \node(X)   {$X$}  ; & \node(Y) {$Y$}; \\
\node(V) {$V$};                   \\};
\draw[<-] (V) -- (X) node[anchor=east]  {$h$};
\draw[->] (V) -- (Y) node[anchor=north]  {$g$};
\draw[->] (X)   -- (Y) node[anchor=south] {$f$};
\end{tikzpicture}

To switch the direction of the arrow, just reverse the order: \draw[->] (Y) -- (V) instead of \draw[->] (V) -- (Y). Also, the V node is centered, so perhaps just increasing the length of the line a bit by adding shorten option as in \draw[->, shorten >=-0.5ex] (Y) -- (V) makes it look more centered. — Peter Grill, Jan 01 '13 at 19:56
have you seen Commutative Diagrams and TikZ and a search for commutative diagrams — cmhughes, Jan 01 '13 at 20:00
@PeterGrill When I compile, I still see the V directly beneath the X,rather than centered and diagonally beneath and to the right of the X, as I would like for it to be. Thanks again. — Michael Dykes, Jan 01 '13 at 20:05
@MichaelDykes: Duhh!!! Sorry about that. Not sure what part of "center" was confusing to me. :-) — Peter Grill, Jan 01 '13 at 20:49

score 5 · Accepted Answer · edited Jun 12 '17 at 06:45

5

Does this solution with tikz-cd help?

\documentclass{standalone}
\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}[column sep=small]
X \arrow{rr}{f} \arrow[swap]{dr}{h}& &Y \arrow{dl}{g}\\
& V & 
\end{tikzcd}    

\end{document}

enter image description here

edited Jun 12 '17 at 06:45

David Carlisle

757,742

answered Jan 01 '13 at 20:12

c.p.

4,636

Actually, it does as this is exactly what I was looking for. In general, what are the differences between tikz and tikz-cd? I mean when is it better to use the latter rather than the former? Thanks again. – Michael Dykes Jan 01 '13 at 20:18
I am unexpert, but as I see it, tikz-cd is a tikz-based package to easily type commutative diagrams. As you can see, the syntaxis is as easy as xymatrix. – c.p. Jan 01 '13 at 20:24
You're welcome. Here is the manual for more information: http://ctan.unixbrain.com/graphics/pgf/contrib/tikz-cd/tikz-cd-doc.pdf – c.p. Jan 01 '13 at 20:33

Fine-tuning a commutative diagram

1 Answers1