Forest
Reference
3.16 The forest coordinate system¶
Unless package options tikzcshack is set to false, TikZ’s implicit node coordinate system [Tantau 2007, §13.2.3] is hacked to accept relative node names.1.
The explicit forest coordinate system is called simply forest and used like this: (forest_cs:⟨forest cs spec⟩); see [Tantau 2007, §13.2.5]. ⟨forest cs spec⟩ is a keylist; the following keys are accepted.
name=⟨node name⟩(forest cs)¶
The node with the given name becomes the current node. The resulting point is its (node) anchor.
id=⟨node id⟩(forest cs)¶
The node with the given name becomes the current node. The resulting point is its (node) anchor.
go=⟨nodewalk⟩(forest cs)¶
Walk the given nodewalk, starting at the current node. The node at the end of the walk becomes the current node. The resulting point is its (node) anchor. The embedded ⟨nodewalk⟩ inherits history from the outer nodewalk.
anchor=⟨anchor⟩(forest cs)¶
The resulting point is the given anchor of the current node.
l=⟨dimen⟩(forest cs)¶
s=⟨dimen⟩(forest cs)¶
Specify the l and s coordinate of the resulting point.
The coordinate system is the node’s ls-coordinate system: its origin is at its (node) anchor; the l-axis points in the direction of the tree growth at the node, which is given by option grow; the s-axis is orthogonal to the l-axis; the positive side is in the counter-clockwise direction from l axis.
The resulting point is computed only after both l and s were given. Any other key is interpreted as a ⟨relative node name⟩[.⟨anchor⟩].
1 Actually, the hack can be switched on and off on the fly, using \iforesttikzcshack.