Pairwise distances between two different point patterns
Computes the distances between pairs of points taken from two different point patterns.
crossdist(X, Y, ..., method="C") crossdist.ppp(X, Y, ..., method="C") crossdist.default(X, Y, x2, y2, ..., method="C")
crossdist.ppp, the arguments
Yshould be point patterns (objects of class
crossdist.default, the arguments
Yshould be numer
crossdist.default, these should be numeric vectors of equal length specifying the location of the second point pattern.
- Ignored by
- String specifying which method of calculation to use.
Given two point patterns, this function computes the Euclidean distance from each point in the first pattern to each point in the second pattern, and returns a matrix containing these distances.
crossdist is generic, with
a method for point patterns (objects of class
and a default method.
The method for point patterns expects two
Y, and returns the matrix
[i,j] entry is the distance from
The default method expects
Y to be numeric vectors
of equal length specifying the coordinates of the first point pattern.
y2 specify the coordinates of the
second point pattern.
method is not normally used. It is
retained only for checking the validity of the software.
method = "interpreted" then the distances are
computed using interpreted R code only. If
(the default) then C code is used.
The C code is faster by a factor of 4.
- A matrix whose
[i,j]entry is the distance from the
i-th point in the first pattern to the
j-th point in the second pattern.
data(cells) d <- crossdist(cells, runifpoint(6)) d <- crossdist(runif(7), runif(7), runif(12), runif(12))