spatstat (version 1.20-2)

simplify.owin: Approximate a Polygon by a Simpler Polygon

Description

Given a polygonal window, this function finds a simpler polygon that approximates it.

Usage

simplify.owin(W, dmin)

Arguments

W

The polygon which is to be simplied. An object of class "owin".

dmin

Numeric value. The smallest permissible length of an edge.

Value

• Another window (object of class "owin") of type "polygonal".

Details

This function simplifies a polygon W by recursively deleting the shortest edge of W until all remaining edges are longer than the specified minimum length dmin, or until there are only three edges left.

The argument W must be a window (object of class "owin"). It should be of type "polygonal". If W is a rectangle, it is returned without alteration.

The simplification algorithm is not yet implemented for binary masks. If W is a mask, an error is generated.

See Also

owin

Examples

data(letterR)
  plot(letterR, col="red")
  plot(simplify.owin(letterR, 0.3), col="blue", add=TRUE)
  data(chorley)
  W <- chorley$window
  plot(W)
  WS <- simplify.owin(W, 2)
  plot(WS, add=TRUE, border="green")
  points(vertices(WS))