maybe related: https://tex.stackexchange.com/questions/142296/tikz-tree-fork-down-edge-labels
但我看不太懂....
在tikz-ext
库中有很方便的<spec>
:|-|
和-|-
等
\documentclass[border=2pt,tikz]{standalone}
\usetikzlibrary{trees,ext.paths.ortho}
\tikzset{
every node/.style={draw,inner sep=2pt},
level/.style={level distance=1.5cm},
level 1/.style={sibling distance=4.5cm},
level 2/.style={sibling distance=2cm}
}
\begin{document}
\begin{tikzpicture}
\node (A) {A}
[edge from parent fork down]
child {node (A1) {A.1}
child {node {A.1.1}}
child {node {A.1.2}}
}
child {node {A.2}
child {node {A.2.1}}
child {node {A.2.2}}
}
;
\path[magenta,draw] (A1.north) |-| (A.south)
node[pos=.25] {.25}
node[pos=.5] {.5}
node[pos=.75] {.75}
node[pos=.875] {.875}
coordinate[pos=.875] (P)
;
\node[inner sep=0pt,circle,pin=above right:P] at (P) {};
\end{tikzpicture}
\end{document}
问 如何确定树图的“动态中点”?