eroded.areas
Areas of Morphological Erosions
Computes the areas of successive morphological erosions of a window.
- Keywords
- spatial
Usage
eroded.areas(w, r)Arguments
- w
- A window.
- r
- Numeric vector of radii at which erosions will be performed.
Details
This function computes the areas of the erosions of the window
w by each of the radii r[i].
The morphological erosion of a set $W$ by a distance $r > 0$ is the subset consisting of all points $x \in W$ such that the distance from $x$ to the boundary of $W$ is greater than or equal to $r$. In other words it is the result of trimming a margin of width $r$ off the set $W$.
The argument r should be a vector of positive numbers.
The argument w should be a window (an object of class
"owin", see owin.object for details)
or can be given in any format acceptable to as.owin().
Unless w is a rectangle, the computation is performed
using a pixel raster approximation.
To compute the eroded window itself, use erode.owin.
Value
- Numeric vector, of the same length as
r, giving the areas of the successive erosions.
See Also
Examples
library(spatstat)
w <- owin(c(0,1),c(0,1))
a <- eroded.areas(w, seq(0.01,0.49,by=0.01))