unique.ppp: Extract Unique Points from a Spatial Point Pattern
Description
Removes any points that are identical to other points
in a spatial point pattern.
Usage
## S3 method for class 'ppp':
unique(x, \dots)
Arguments
x
A spatial point pattern
(object of class "ppp").
...
Ignored.
Value
Another point pattern object.
Details
This is a method for the generic function unique for
point pattern datasets (of class "ppp", see ppp.object).
Two points in a point pattern are deemed to be identical
if their $x,y$ coordinates are the same,
and their marks are also the same (if they carry marks).
The Examples section illustrates how it is possible for
a point pattern to contain a pair of identical points.
This function removes duplicate points in x,
and returns a point pattern.