Make a lozenge diagram

Question

I would like to create a lozenge diagram with the package \xymatrix. Here is the code I wrote :

\[\xymatrix{
  & M\ar@{-}[ld]^{n}_{G} \ar@{-}[rd]^{m^2}& \\
  H\ar@{-}[rd]^{m^2} && Z(M)\ar@{-}[ld]^{n}_{G} \\
  & K& \\
  }\]

And here is the result.

I would like to know how to make it more beautiful : it looks like that the right part of the lozenge is longer than the left part. Thank you for your help !

One possibility is to use Z\rlap{(M)}. Not elegant solution, but satisfactory one. — Sigur, Apr 11 '22 at 10:16

score 0 · Accepted Answer · answered Apr 11 '22 at 10:46

I suggest to use tikz-cd and to make the two objects in the middle row the same width.

\documentclass{article}
\usepackage{amsmath,mathtools}
\usepackage{tikz-cd}
\begin{document}
[
\begin{tikzcd}[arrows=dash]
& M \arrow[ld,"G"',"n"] \arrow[rd,"m^2"] \
\mathmakebox[0.5em][r]{H} \arrow[rd,"m^2"] &&
\mathmakebox[0.5em][l]{Z(M)} \arrow[ld,"G"',"n"] \
& K
\end{tikzcd}
]
\end{document}

A similar trick almost works with Xy-pic.

\[
\xymatrix{
  & M\ar@{-}[ld]^{n}_{G} \ar@{-}[rd]^{m^2}& \\
  \mathmakebox[0.5em][r]{H} \ar@{-}[rd]^{m^2} &&
  \mathmakebox[0.5em][l]{Z(M)} \ar@{-}[ld]^{n}_{G} \\
  & K& \\
}
\]

Make a lozenge diagram

1 Answers1