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Arc Geometry

Source: R/geometry-constructors.R
arc.Rd

Create one or more circular or elliptic arcs.

Usage

arc(
  x = 0,
  y = 0,
  radiusX = 1,
  radiusY = radiusX,
  startAngle = 0,
  endAngle = 2 * pi,
  nPoints = 100
)

Arguments

x, y

coordinates of the arc centre

radiusX, radiusY

horizontal and vertical radius

startAngle, endAngle

start and end angle in radians

nPoints

number of points used to approximate the arc

Value

An object inheriting from class "arcGeometry".

See also

Other geometry.structures: band(), bezier(), circle(), ellipse(), polygonX(), regPolygon(), ring()

Examples

canvas(xlim = c(-2, 2))

# a quarter of a circle
lines(arc(radiusX = 1.5, startAngle = 0, endAngle = pi/2), lwd = 2)

# elliptic arcs, vectors of radii yield a collection of arcs
a <- arc(radiusX = c(0.5, 1), radiusY = c(1, 1.8),
         startAngle = pi, endAngle = 3*pi/2)
lines(a, col = "red")