spatstat.geom (version 3.2-5)

whichhalfplane: Test Which Side of Infinite Line a Point Falls On

Description

Given an infinite line and a spatial point location, determine which side of the line the point falls on.

Usage

whichhalfplane(L, x, y = NULL)

Value

A logical matrix.

Arguments

L

Object of class "infline" specifying one or more infinite straight lines in two dimensions.

x,y

Arguments acceptable to xy.coords specifying the locations of the points.

Author

Adrian Baddeley [email protected].

Details

An infinite line \(L\) divides the two-dimensional plane into two half-planes. This function returns a matrix M of logical values in which M[i,j] = TRUE if the jth spatial point lies below or to the left of the ith line.

See Also

infline

Examples

  L <- infline(p=runif(3), theta=runif(3, max=2*pi))
  X <- runifrect(4)
  whichhalfplane(L, X)