Dynkin-diagrams package labels problem

Question

i'm struggling with the labels of some biforcate dynkin-diagram

my code is the following

\usepackage{dynkin-diagrams}
\begin{document

\begin{center}
 \begin{dynkinDiagram}
  \dynkin[labels={m \cosh \theta, 1,2,3,,n-2,n-1,n,n+1}, scale=1.8, extended]D{*ooo...oooo}
 \end{dynkinDiagram}
\end{center}

\end{document}

but my output looks like this. unlabel

I would really appreciate some help, I have tried different combinations but nothing seems to work.

Answer 1

Here is another way that might work. We can create a Dynkin diagram environment, put in place the labels that seem to work ok, and then for the difficult label, use TikZ directly inside the environment. Maybe that is more stable than using the labels from my package. (It gives the same picture as above.)

\documentclass{article}
\usepackage{dynkin-diagrams}
\begin{document}
\begin{center}
\begin{dynkinDiagram}[labels={,1,2,3,,n-2,n-1,n,n+1},
         label directions={,,left,,,,right,,},
         scale=1.8,
         extended] D{*ooo...oooo}    
\node[left] at (root 0) {\(m\,\cosh\theta\)};
\end{dynkinDiagram}
\end{center}
\end{document}

Answer 2

There are two issues: first you can't use \dynkin inside of a dynkinDiagram environment, you have to choose one or the other. Second for some reason the label list parser does not like \cosh, so you can replace that with \text{cosh}. To add a bit of space around the operator I added \, in the code below.

To position the labels I added label directions={} in the example below.

Note that I don't know anything about Dynkin diagrams, so probably the end result is not fully correct - but it does have labels.

MWE:

\documentclass{article}
\usepackage{dynkin-diagrams}
\begin{document}
\begin{center}
 \dynkin[labels={m\,\text{cosh}\,\theta,1,2,3,,n-2,n-1,n,n+1},
         label directions={,,left,,,,right,,},
         scale=1.8,
         extended] D{*ooo...oooo}
\end{center}
\end{document}

Result:

---

Following the comment from egreg below, you can also robustify \cosh with etoolbox to make the command survive processing by dynkin-diagrams. This allows to use the original command instead of a poorly spaced \text{cosh}. Note that if you want to use other non-robust commands then you need to robustify those separately.

\documentclass{article}
\usepackage{etoolbox}
\usepackage{dynkin-diagrams}
\robustify{\cosh}
\begin{document}
\begin{center}
 \dynkin[labels={m\cosh\theta,1,2,3,,n-2,n-1,n,n+1},
         label directions={,,left,,,,right,,},
         scale=1.8,
         extended] D{*ooo...oooo}
\end{center}
\end{document}