arrow: Describe arrows to add to a line.
Description
Produces a description of what arrows to add to a line.
The result can be passed to a function that draws a line,
e.g., grid.lines.
Usage
arrow(angle = 30, length = unit(0.25, "inches"),
ends = "last", type = "open")Arguments
angle
The angle of the arrow head in degrees (smaller numbers
produce narrower, pointier arrows). Essentially describes
the width of the arrow head.
length
A unit specifying the length of the arrow head (from tip
to base).
ends
One of "last", "first", or "both",
indicating which ends of the line to draw arrow heads.
type
One of "open" or "closed" indicating
whether the arrow head should be a closed triangle.