multiplicity.ppp: Count Multiplicity of Duplicate Points
Description
Counts the number of duplicates for each point
in a spatial point pattern.
Usage
multiplicity.ppp(x)
Arguments
x
A spatial point pattern
(object of class "ppp").
Value
A vector of integers (multiplicities) of length equal to the
number of points in x.
Details
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.
For each point in x, this function counts how many
points are identical to it, and returns the vector of counts.
X <- ppp(c(1,1,0.5), c(2,2,1), window=square(3))
m <- multiplicity.ppp(X)
# unique points in X, marked by multiplicity first <- !duplicated(X)
Y <- X[first] %mark% m[first]