The "npc" unit
is not absolute, i.e.
it depends on the relation between height and width within
the current viewport. We therefore need to change these values
to the value most likely intended. This is believed to be the
main direction of the arrow as specified by the first and last
bezier control points x
and y
.
getAbsoluteWidth(w, default.units, x = x, y = y)
The width transformed into a unit
of "mm"
The width that is to be changed
A string indicating the default units to use
if x
or y
are only given as numeric vectors.
A numeric vector or unit object specifying x-locations of spline control points.
A numeric vector or unit object specifying y-locations of spline control points.