The ob_bezier (i.e., bezier curve) class — ob

The ob_bezier is specified with an ob_point object that contains at least 2 points, the start and the end. Such a "curve" would actually be a straight line segment. If three points are specified, the middle point is a control point, and a quadratic bezier curve will result. Higher-order bezier curves can be created by having more control points in the middle.

Usage

ob_bezier(
  p = class_missing,
  label = class_missing,
  label_sloped = TRUE,
  n = 360,
  alpha = class_missing,
  arrow_head = class_missing,
  arrow_fins = class_missing,
  arrowhead_length = class_missing,
  length_head = class_missing,
  length_fins = class_missing,
  color = class_missing,
  fill = class_missing,
  lineend = class_missing,
  linejoin = class_missing,
  linewidth = class_missing,
  linewidth_fins = class_missing,
  linewidth_head = class_missing,
  linetype = class_missing,
  resect = class_missing,
  resect_fins = class_missing,
  resect_head = class_missing,
  stroke_color = class_missing,
  stroke_width = class_missing,
  style = class_missing,
  ...
)

Arguments

p: ob_point or list of ob_points
label: A character, angle, or label object
label_sloped: A logical value indicating whether the label should be sloped with the curve
n: Number of points in a polygon, circle, arc, or ellipse
alpha: numeric value for alpha transparency
arrow_head: A 2-column matrix of polygon points
arrow_fins: A 2-column matrix of polygon points
arrowhead_length: Determines the size of the arrow ornaments. This parameter becomes the length parameter in ggarrow functions. Numeric values set the ornament size relative to the linewidth. A unit value sets the ornament size in an absolute manner.
length_head: Determines the size of the arrow head. Numeric values set the ornament size relative to the linewidth. A 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 unit value sets the ornament size in an absolute manner. From ggarrow.
color: character string for color
fill: character string for fill color
lineend: Line end style (round, butt, square).
linejoin: Line join style (round, mitre, bevel).
linewidth: Width of lines
linewidth_fins: Line width for arrow fins
linewidth_head: Line width for arrow fins
linetype: type of lines
resect: A numeric(1) denoting millimeters or to shorten the arrow head and fins.
resect_fins: A numeric(1) denoting millimeters or to shorten the arrow fins
resect_head: A numeric(1) denoting millimeters or to shorten the arrow head.
stroke_color: Color of point border line
stroke_width: Stroke width in arrows
style: Gets and sets the styles associated with ob_beziers
...: <dynamic-dots> properties passed to style

Details

If you wish to specify multiple bezier curves, you must supply a list of ob_point objects. When plotted, the ob_bezier function uses the bezier::bezier function to create the point coordinates of the curve and the ggarrow::geom_arrow function to create the geom.

Slots

length: The number of curves in the ob_bezier object
tibble: Gets a tibble (data.frame) containing parameters and styles used by ggarrow::geom_arrow.
geom: A function that converts the object to a geom. Any additional parameters are passed to ggarrow::geom_arrow.
midpoint: A function that selects 1 or more midpoints of the ob_bezier. The position argument can be between 0 and 1. Additional arguments are passed to the ob_point's style object.
aesthetics: A list of information about the ob_bezier's aesthetic properties

Examples

library(ggplot2)
control_points <- ob_point(c(0,1,2,4), c(0,4,0,0))
ggplot() + coord_equal() +
  ob_bezier(control_points, color = "blue") +
  ob_path(control_points, linetype = "dashed", linewidth = .5) +
  control_points