Package 'earthcircle'

Generate coordinates of an "earth" circle.

Description

A circle on the ground for every input longitude,latitude.

Usage

earthcircle(
  x,
  y = NULL,
  scale = 3 * 1852 * 60,
  ...,
  n = 36,
  from = 0,
  to = 2 * pi
)

Arguments

x	longitude of central location for circle, or lon,lat together in matrix, data frame, or list
y	latitude of location (ignored if 'x' includes y)
scale	the scale of the circle, large enough default to see on world maps
...	ignored currently
n	the number of coordinates to provide each circle
from	the minimum radial angle (default 0)
to	the maximum radial angle

Value

matrix of circle coordinates (separated by NA rows)

Examples

x <- earthcircle(cbind(c(0, -50), c(0, -90)), scale = 1e6, from = 0, to = pi)
plot(earthcircle:::.prj(x, "+proj=laea +lat_0=-90"), asp = 1, type = "l")

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