Learn R Programming

spatstat.geom (version 3.2-5)

vertices: Vertices of a Window

Description

Finds the vertices of a window, or similar object.

Usage

vertices(w)

# S3 method for owin vertices(w)

Value

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

Arguments

w

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

Author

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

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

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.

See Also

owin.object.

Examples

Run this code
  vert <- vertices(letterR)

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

Run the code above in your browser using DataLab