Computes the matrix of distances between all pairs of points in a point pattern.
# S3 method for ppp
pairdist(X, ...,
periodic=FALSE, method="C", squared=FALSE, metric=NULL)A square matrix whose [i,j] entry is the distance
between the points numbered i and j.
A point pattern (object of class "ppp").
Ignored.
Logical. Specifies whether to apply a periodic edge correction.
String specifying which method of calculation to use.
Values are "C" and "interpreted".
Usually not specified.
Logical. If squared=TRUE, the squared distances are
returned instead (this computation is faster).
Optional. A metric (object of class "metric")
that will be used to define and compute the distances.
Pavel Grabarnik pavel.grabar@issp.serpukhov.su and Adrian Baddeley Adrian.Baddeley@curtin.edu.au.
This is a method for the generic function pairdist.
Given a point pattern X (an object of class "ppp"),
this function computes the Euclidean distances between all pairs of
points in X, and returns the matrix of distances.
Alternatively if 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.
If 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).
The argument method is not normally used. It is
retained only for checking the validity of the software.
If method = "interpreted" then the distances are
computed using interpreted R code only. If method="C"
(the default) then C code is used. The C code is somewhat faster.
pairdist,
pairdist.default,
pairdist.psp,
crossdist,
nndist,
Kest
d <- pairdist(cells)
d <- pairdist(cells, periodic=TRUE)
d <- pairdist(cells, squared=TRUE)
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