create double-headed arrow paths indicating variance

Usage

ob_covariance(
  x,
  y,
  where = NULL,
  bend = 0,
  looseness = 1,
  arrow_head = the$arrow_head,
  length_head = 7,
  length_fins = 7,
  resect = 2,
  ...
)

Arguments

x: object
y: object
where: exit angle. Can be numeric (degrees), degree, radian, turn, or named direction (e.g., "northwest", "east", "below", "left")
bend: Angle by which the control points are rotated. Can be numeric (degrees), degree, radian, turn, or named direction (e.g., "northwest", "east", "below", "left"). Defaults to 0
looseness: distance of control points as a ratio of the distance to the object's center (e.g., in a circle of radius 1, looseness = 1.5 means that that the control points will be 1.5 units from the start and end points.)
arrow_head: A 2-column matrix of polygon points
length_head: Determines the size of the arrow head. Numeric values set the ornament size relative to the linewidth. A grid::unit value sets the ornament size in an absolute manner. From ggarrow.
length_fins: Determines the size of the arrow fins. Numeric values set the ornament size relative to the linewidth. A grid::unit value sets the ornament size in an absolute manner. From ggarrow.
resect: A numeric(1) denoting millimeters or grid::unit to shorten the arrow head and fins.
...: <dynamic-dots> properties passed to style

Value

An ob_bezier object

Examples

ggdiagram() +
  {x <- ob_circle(ob_point(c(-2, 2), 0))} +
  ob_covariance(x = x[1],
                y = x[2],
                label = ob_label("A"))


ggdiagram() +
  x +
  ob_covariance(x = x[1],
                y = x[2],
                label = ob_label("A"),
                where = -45,
                looseness = .75)