ngon {maptree}R Documentation

Outline or Fill a Regular Polygon

Description

Draws a regular polygon at specified coordinates as an outline or shaded.

Usage

  ngon (xydc, n=4, type=1)

Arguments

xydc four element vector with x and y coordinates of center, d diameter in mm, and c color.
n number of sides for polygon (>8 => circle).
type type=1 => interior filled, type=2 => edge, type=3 => both.

Details

Uses polygon to draw shaded polygons and lines for outline. If n is odd, there is a vertex at (0, d/2), otherwise the midpoint of a side is at (0, d/2).

Value

Invisible.

Author(s)

Denis White, white.denis@epa.gov

See Also

polygon, lines, map.key, map.groups

Examples

  plot (c(0,1), c(0,1), type="n")
  ngon (c(.5, .5, 10, "blue"), n=3)
  apply (cbind (runif(8), runif(8), 6, 2), 1, ngon)