crossdist.ppx.Rd
\name{crossdist.ppx}
\alias{crossdist.ppx}
\title{Pairwise Distances Between Two Different Multi-Dimensional Point Patterns}
\description{
Computes the distances between pairs of points
taken from two different multi-dimensional point patterns.
}
\usage{
\method{crossdist}{ppx}(X, Y, \dots)
}
\arguments{
\item{X,Y}{
Multi-dimensional point patterns (objects of class \code{"ppx"}).
}
\item{\dots}{
Arguments passed to \code{\link{coords.ppx}} to determine
which coordinates should be used.
}
}
\value{
A matrix whose \code{[i,j]} entry is the distance
from the \code{i}-th point in \code{X}
to the \code{j}-th point in \code{Y}.
}
\details{
Given two point patterns in multi-dimensional space,
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 \code{\link{crossdist}}
for three-dimensional point patterns (objects of class \code{"ppx"}).
This function expects two multidimensional
point patterns \code{X} and \code{Y}, and returns the matrix
whose \code{[i,j]} entry is the distance from \code{X[i]} to
\code{Y[j]}.
By default, both spatial and temporal coordinates are extracted.
To obtain the spatial distance between points in a space-time point
pattern, set \code{temporal=FALSE}.
}
\seealso{
\code{\link{crossdist}},
\code{\link{pairdist}},
\code{\link{nndist}}
}
\examples{
df <- data.frame(x=runif(3),y=runif(3),z=runif(3),w=runif(3))
X <- ppx(data=df)
df <- data.frame(x=runif(5),y=runif(5),z=runif(5),w=runif(5))
Y <- ppx(data=df)
d <- crossdist(X, Y)
}
\author{
Adrian Baddeley
\email{Adrian.Baddeley@csiro.au}
\url{http://www.maths.uwa.edu.au/~adrian/}
}
\keyword{spatial}
\keyword{math}