# Dynkin-diagrams package arrow size modificaiton

I'm currently trying to draw something with the dynkin-diagrams package and I don't really know how to modify the arrows that are produced. The documentation explains how one can reverse the arrow, but not how to enlarge it... Consider as example the code:

\documentclass{article}
\usepackage{dynkin-diagrams}
\begin{document}
\begin{dynkinDiagram}[indefinite edge/.style={ultra thick,densely dashed},
o/.style={ultra thick,fill=black!30!white,draw=black},
edge length=2cm,
edge/.style={ultra thick},
\end{dynkinDiagram}
\end{document}


resulting in

I tried to modify arrow/.style, but I'm doing something wrong since no changes happen. Any hints are appreciated.

• I will put a new version up on CTAN soon to deal with this, but I need to test it a little more first. Feb 18, 2020 at 13:19

You could exploit the fact that the dynkin-diagrams package feeds the color to the arrow head using

\path[-{Computer Modern Rightarrow[\dynkin@arrow@color]},


This means you can pass any arrows parameters to the color key, i.e. not just the color but also the length, width and line width (and any other viable arrows parameter of section 16.5 Reference: Arrow Tips of the pgf manual v3.1.5).

\documentclass{article}
\usepackage{dynkin-diagrams}
\begin{document}
\begin{dynkinDiagram}[indefinite edge/.style={ultra thick,densely dashed},
o/.style={ultra thick,fill=black!30!white,draw=black},
edge length=2cm,
edge/.style={ultra thick},
arrow color={black,length=3mm,width=5mm,line width=2pt}]{F}{oooo}
\end{dynkinDiagram}
\end{document}


Today's new version of dynkin-diagrams on CTAN allows using the expression arrow style as a synonym for arrow color, so that you can use the same solution as Schrödinger's cat, but it looks a little more natural. I suggest using tikzset to make global settings for your document, so that all Dynkin diagrams have the same style.

\documentclass{article}
\usepackage{dynkin-diagrams}
\tikzset{
/Dynkin diagram,
indefinite edge/.style={
ultra thick,
densely dashed
},
o/.style={
ultra thick,
fill=black!30!white,
draw=black
},
edge length=2cm,
edge/.style={ultra thick},
arrow style={black,
length=3mm,
width=5mm,
line width=2pt
},