forest respecify branch positions 2

Question

following on from previous question

Example Problem:

\documentclass[margin=3mm]{standalone}%
\usepackage{forest}
\usetikzlibrary{positioning}

\begin{document}
    \begin{forest}
for tree={
inner xsep=0pt,
s sep=9mm,
l sep=7mm}
    [VP
    [DP]
      [V'
        [A, name=a]
        [DP]
      ]
]
\begin{scope}[inner xsep=0pt, node distance=7mm and 0mm]
\node (b) [right=of a] {B};
\node (c) [right=of b] {C};
\node (x) [below=of c] {XXX};
\draw (c) -- (x);
\end{scope}
    \end{forest}
\end{document}

XXX is now below ABC but if I want to do these sort of rearrangements at multiple levels (e.g. XXX now should point to the 1 in 123 in a node at a level below, and the 3 then points to node below it, can I do it in forest, or do I need to manually build the tree in tikz?

Answer 1

You can do that all within forest without having to resort to place extra stuff with TikZ methods. One possibility is to play with anchors, note that there are different anchors: node anchors, child anchors and parent anchors.

\documentclass[margin=3mm]{standalone}%
\usepackage{forest}
\usetikzlibrary{positioning}

\begin{document}
    \begin{forest}
for tree={
inner xsep=0pt,
s sep=9mm,
l sep=7mm}
    [VP
    [DP]
      [V'
        [ABC, name=a,parent anchor=-45
         [XXX,anchor=135]]
        [DP]
      ]
]
    \end{forest}
\end{document}

The numbers are just angles. In order to make V' connect to A in ABC just add ,child anchor=120.

\documentclass[margin=3mm]{standalone}%
\usepackage{forest}
\usetikzlibrary{positioning}

\begin{document}
    \begin{forest}
for tree={
inner xsep=0pt,
s sep=9mm,
l sep=7mm}
    [VP
    [DP]
      [V'
        [ABC, name=a,parent anchor=-45,child anchor=120
         [XXX,anchor=135]]
        [DP]
      ]
]
    \end{forest}
\end{document}