Diagrams – How to Draw Commutative Diagrams in LaTeX

Question

This question already has answers here:

How to draw commutative diagrams?

(2 answers)

Closed 7 years ago.

I would like to learn to make commutative rectangles using Tikz. How can I do that? I have tried

\[\begin{tikzcd}
A \arrow{r}{\varphi} \arrow[swap]{dd}{g\circ f} & B \arrow{d}{g} \\
& C
\end{tikzcd}
\]

but it draws only a triangle.

Answer 1

I don't know what you exactly wanted to draw, so I reproduce one of the diagrams from your link, showing how to do it with pst-node and with tikz-cd. One of the main differences is that in pstricks you first describe the nodes, then the arrows, while with tikz-cd, nodes and arrows are described simultaneously.

I load auto-pst-pdf, as pdflatex doesn't support postscript instructions. You have to set the --enable-write18 compiler switch (MiKTeX) or -shell-escape (TeX Live, MacTeX). Alternatively, you can compile with xelatex.

\documentclass{article}
\usepackage{pst-node}
\uspackage{auto-pst-pdf}
\usepackage{tikz-cd} 

\begin{document}
%
 \[ \psset{arrows=->, arrowinset=0.25, linewidth=0.6pt, nodesep=3pt, labelsep=2pt, rowsep=0.7cm, colsep = 1.1cm, shortput =tablr}
 \everypsbox{\scriptstyle}
 \begin{psmatrix}
 A & B\\%
 A_f & B_g
 %%%
 \ncline{1,1}{1,2}^{\varphi} \ncline{1,1}{2,1} <{\varrho_f }
 \ncline{1,2}{2,2} > {\varrho_g}
 \ncline{2,1}{2,2}^{\varphi_f}
 \end{psmatrix}
 \]

\[ \begin{tikzcd}
A \arrow{r}{\varphi} \arrow[swap]{d}{\varrho_f} & B \arrow{d}{\varrho_g} \\%
A_f \arrow{r}{\varphi_f}& B_g
\end{tikzcd}
\]
\end{document}