yyInternal node and tip y coordinates
xxInternal
node and tip x coordinates
phyA phylo4
or phylo4d
object
segsA list of h0x, h1x, v0x, v1x
and h0y, h1y,
v0y, v1y
describing the start and end points for the plot line segments
torderThe tip order provided as tip.order
or if NULL the
preoder tip order
eorderThe an index of the reordered edges
compared to the result of edges(phy)