vertices

0th

Percentile

Vertices of a Window

Finds the vertices of a window, or similar object.

Keywords
spatial, math
Usage
vertices(w) # S3 method for 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.

owin.object.

Aliases
• vertices
• vertices.owin
Examples
# NOT RUN {
data(letterR)
vert <- vertices(letterR)

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