# Downwards arrows in forest

I have the following tree and want the connections between nodes to be arrows rather than plain lines. Is this possible? I found the edge option, but this does not provide an appropriate option.

\documentclass{article}

\usepackage{forest}
\forestset{
sn edges/.style={for tree={parent anchor=south, child anchor=north,align=center,base=bottom,where n children=0{tier=word}{}}},
background tree/.style={for tree={text opacity=0.2,draw opacity=0.2,edge={draw opacity=0.2}}}
}

\begin{document}

\begin{forest}
sn edges
[D-Struktur
[S-Struktur
[Tilgungsregeln{,}\\Filter{,} phonol. Regeln
[Phonetische\\Form (PF)]]
[Regeln des anaphorischen Bezugs{,}\\der Quantifizierung und der Kontrolle
[Logische\\Form (LF)]]]]
\end{forest}

\end{document}


Use edge option to indicate which kind of line between nodes do you need.

edge={->}


would be the easiest. You have an example forest documentation page 19.

\documentclass{article}

\usepackage{forest}
\forestset{
sn edges/.style={for tree={parent anchor=south, child anchor=north,align=center,edge={->},base=bottom,where n children=0{tier=word}{}}},
background tree/.style={for tree={text opacity=0.2,draw opacity=0.2,edge={draw opacity=0.2}}}
}

\begin{document}

\begin{forest}
sn edges
[D-Struktur
[S-Struktur
[Tilgungsregeln{,}\\Filter{,} phonol. Regeln
[Phonetische\\Form (PF)]]
[Regeln des anaphorischen Bezugs{,}\\der Quantifizierung und der Kontrolle
[Logische\\Form (LF)]]]]
\end{forest}

\end{document}


• Since I see this 'forest' package for the first time, I was just wondering...is it also possible to create trees horizontally using this? – Abhimanyu Arora Jul 2 '14 at 11:10
• Yes, see the documentation. – user2478 Jul 2 '14 at 11:57
• @Ignasi How would it be possible to have an arrow (or arrows) manually? (Say, at a specific edge only.) – blackened May 6 '18 at 11:29