Computes the matrix of distances between all pairs of points in a point pattern.
## S3 method for class 'ppp': pairdist(X, \dots, periodic=FALSE, method="C", squared=FALSE)
- A point pattern (object of class
- Logical. Specifies whether to apply a periodic edge correction.
- String specifying which method of calculation to use.
"interpreted". Usually not specified.
- Logical. If
squared=TRUE, the squared distances are returned instead (this computation is faster).
This is a method for the generic function
Given a point pattern
X (an object of class
this function computes the Euclidean distances between all pairs of
X, and returns the matrix of distances.
periodic=TRUE and the window containing
X is a
rectangle, 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.
squared=TRUE then the squared Euclidean distances
$d^2$ are returned, instead of the Euclidean distances $d$.
The squared distances are faster to calculate, and are sufficient for
many purposes (such as finding the nearest neighbour of a point).
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 somewhat faster.
- A square matrix whose
[i,j]entry is the distance between the points numbered
data(cells) d <- pairdist(cells) d <- pairdist(cells, periodic=TRUE) d <- pairdist(cells, squared=TRUE)