https://github.com/cran/spatstat
Tip revision: 8ba424ae2810d8985064bafb88d4ad7c421f84a5 authored by Adrian Baddeley on 09 May 2016, 10:08:26 UTC
version 1.45-2
version 1.45-2
Tip revision: 8ba424a
multiplicity.ppp.Rd
\name{multiplicity.ppp}
\alias{multiplicity}
\alias{multiplicity.default}
\alias{multiplicity.data.frame}
\alias{multiplicity.ppp}
\alias{multiplicity.ppx}
\title{Count Multiplicity of Duplicate Points}
\description{
Counts the number of duplicates for each point
in a spatial point pattern.
}
\usage{
multiplicity(x)
\method{multiplicity}{ppp}(x)
\method{multiplicity}{ppx}(x)
\method{multiplicity}{data.frame}(x)
\method{multiplicity}{default}(x)
}
\arguments{
\item{x}{
A spatial point pattern
(object of class \code{"ppp"} or \code{"ppx"})
or a vector, matrix or data frame.
}
}
\value{
A vector of integers (multiplicities) of length equal to the
number of points in \code{x}.
}
\details{
Two points in a point pattern are deemed to be identical
if their \eqn{x,y} coordinates are the same,
and their marks are also the same (if they carry marks).
The Examples section illustrates how it is possible for
a point pattern to contain a pair of identical points.
For each point in \code{x}, the function \code{multiplicity} counts how many
points are identical to it, and returns the vector of counts.
The argument \code{x} can also be a vector, a matrix or a data frame.
When \code{x} is a vector, \code{m <- multiplicity(x)} is a vector
of the same length as \code{x}, and \code{m[i]} is the
number of elements of \code{x} that are identical to \code{x[i]}.
When \code{x} is a matrix or data frame,
\code{m <- multiplicity(x)} is a vector
of length equal to the number of rows of \code{x}, and \code{m[i]}
is the number of rows of \code{x} that are identical to
the \code{i}th row.
}
\seealso{
\code{\link{ppp.object}},
\code{\link{duplicated.ppp}},
\code{\link{unique.ppp}}
}
\examples{
X <- ppp(c(1,1,0.5,1), c(2,2,1,2), window=square(3), check=FALSE)
m <- multiplicity(X)
# unique points in X, marked by their multiplicity
first <- !duplicated(X)
Y <- X[first] \%mark\% m[first]
}
\author{Adrian Baddeley \email{Adrian.Baddeley@curtin.edu.au}
,
Rolf Turner \email{r.turner@auckland.ac.nz}
and Sebastian Meyer.
}
\keyword{spatial}
\keyword{utilities}