Pairwise distances between two different point patterns
Computes the distances between pairs of points taken from two different point patterns.
## S3 method for class 'ppp': crossdist(X, Y, \dots, periodic=FALSE, method="C", squared=FALSE)
- Point patterns (objects of class
- Logical. Specifies whether to apply a periodic edge correction.
- String specifying which method of calculation to use.
- Logical. If
squared=TRUE, the squared distances are returned instead (this computation is faster).
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.
This is a method for the generic function
for point patterns (objects of class
This function expects two
Y, and returns the matrix
[i,j] entry is the distance from
periodic=TRUE, then provided the windows
Y are identical and are rectangular,
then the distances will be computed in the `periodic'
sense (also known as `torus' distance): opposite edges of the
rectangle are regarded as equivalent.
This is meaningless if the window is not a rectangle.
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
j-th point in
data(cells) d <- crossdist(cells, runifpoint(6)) d <- crossdist(cells, runifpoint(6), periodic=TRUE)