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

whichhalfplane {spatstat.geom} | R Documentation

## 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)

### 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.

### 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 `j`th spatial point lies below or to the left of the `i`th line.

### Value

A logical matrix.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au.

### See Also

`infline`

### Examples

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

[Package spatstat.geom version 2.3-2 Index]