crossdist.ppp {spatstat}R Documentation

Pairwise distances between two different point patterns

Description

Computes the distances between pairs of points taken from two different point patterns.

Usage

  ## S3 method for class 'ppp':
  crossdist(X, Y, ..., method="C")

Arguments

X,Y Point patterns (objects of class "ppp").
... Ignored.
method String specifying which method of calculation to use. Values are "C" and "interpreted".

Details

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 crossdist for point patterns (objects of class "ppp").

This function expects two point patterns X and Y, and returns the matrix whose [i,j] entry is the distance from X[i] to Y[j].

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 faster by a factor of 4.

Value

A matrix whose [i,j] entry is the distance from the i-th point in X to the j-th point in Y.

Author(s)

Pavel Grabarnik pavel.grabar@issp.serpukhov.su and Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/

See Also

crossdist, crossdist.default, crossdist.psp, pairdist, nndist, Gest

Examples

   data(cells)
   d <- crossdist(cells, runifpoint(6))

[Package spatstat version 1.8-9 Index]