Count Multiplicity of Duplicate Points

Description

Counts the number of duplicates for each point in a spatial point pattern.

Usage

 multiplicity.ppp(x)

Arguments

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.

Value

A vector of integers (multiplicities) of length equal to the number of points in x.

Author(s)

Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf

See Also

ppp.object, duplicated.ppp, unique.ppp

Examples

   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]