circle function

Draw circle with a given radius

Draw circle with a given radius

Draws a filled circle with a certain radius (in existing plot's units) using polygon and sin

circle(x, y, r, locnum = 100, ...)

Arguments

  • x: x coordinate of points, numeric value of length 1
  • y: y coordinate
  • r: radius of the circle in units of current plot. Can have two values for an ellipse.
  • locnum: number of calculated points on the circle (more means smoother but slower). DEFAULT: 100
  • ...: further arguments passed to polygon, like col, border, lwd

Returns

data.frame of coordinates, invisible

Note

If circles look like ellipsis, use plot(... asp=1)

Examples

plot(1:20, type="n", asp=1) circle(5,5, r=3) # 1:1 aspect shows they're really circles and not ellipses. circle(15,10, r=4, locnum=12, col=2, border=4, lwd=3) # can not be vectorized: x <- sample(1:20, 15) ; y <- sample(1:20, 15) ; r <- runif(20)*3 circle(x,y,r, col=rgb(1,0.5,0,alpha=0.4), border=NA) for(i in 1:15) circle(x[i],y[i],r[i], col=rgb(1,0.5,0,alpha=0.4), border=NA)

See Also

symbols, polygon

Author(s)

Berry Boessenkool, berry-b@gmx.de , 2012

  • Maintainer: Berry Boessenkool
  • License: GPL (>= 2)
  • Last published: 2024-02-16