R: Vertices of a Window

vertices {spatstat} | R Documentation

## Vertices of a Window

### Description

Finds the vertices of a window, or similar object.

### Usage

     vertices(w)

     ## S3 method for class 'owin'
    vertices(w)

### Arguments

`w` | A window (object of class `"owin"`) or similar object.

### Details

This function computes the vertices (‘corners’) of a spatial window or other object.

For `vertices.owin`, the argument `w` should be a window (an object of class `"owin"`, see `owin.object` for details).

If `w` is a rectangle, the coordinates of the four corner points are returned.

If `w` is a polygonal window (consisting of one or more polygons), the coordinates of the vertices of all polygons are returned.

If `w` is a binary mask, then a ‘boundary pixel’ is defined to be a pixel inside the window which has at least one neighbour outside the window. The coordinates of the centres of all boundary pixels are returned.

### Value

A list with components `x` and `y` giving the coordinates of the vertices.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### See Also

`owin.object`.

### Examples

      data(letterR)
      vert <- vertices(letterR)

      plot(letterR, main="Polygonal vertices")
      points(vert)
      plot(letterR, main="Boundary pixels")
      points(vertices(as.mask(letterR)))

[Package spatstat version 1.54-0 Index]