Revision d606122dc24b56ecf537d55eda38f4bf5ac4de1f authored by Adrian Baddeley on 25 October 2010, 10:40:51 UTC, committed by cran-robot on 25 October 2010, 10:40:51 UTC
1 parent 66bc933
as.tess.Rd
\name{as.tess}
\alias{as.tess}
\alias{as.tess.tess}
\alias{as.tess.im}
\alias{as.tess.owin}
\alias{as.tess.quadratcount}
\alias{as.tess.quadrattest}
\alias{as.tess.list}
\title{Convert Data To Tessellation}
\description{
Converts data specifying a tessellation,
in any of several formats, into an object of class \code{"tess"}.
}
\usage{
as.tess(X)
\method{as.tess}{tess}(X)
\method{as.tess}{im}(X)
\method{as.tess}{owin}(X)
\method{as.tess}{quadratcount}(X)
\method{as.tess}{quadrattest}(X)
\method{as.tess}{list}(X)
}
\arguments{
\item{X}{Data to be converted to a tessellation.}
}
\value{
An object of class \code{"tess"} specifying a tessellation.
}
\details{
A tessellation is a collection of disjoint spatial regions
(called \emph{tiles}) that fit together to form a larger spatial
region. This command creates an object of class \code{"tess"} that
represents a tessellation.
This function converts data in any of several formats
into an object of class \code{"tess"} for use by the \pkg{spatstat}
package. The argument \code{X} may be
\itemize{
\item
an object of class \code{"tess"}.
The object will be stripped of any extraneous attributes
and returned.
\item
a pixel image (object of class \code{"im"}) with pixel values that
are logical or factor values. Each level of the factor will
determine a tile of the tessellation.
\item
a window (object of class \code{"owin"}). The result will be a
tessellation consisting of a single tile.
\item
a set of quadrat counts (object of class \code{"quadratcount"})
returned by the command \code{\link{quadratcount}}.
The quadrats
used to generate the counts will be extracted and returned as a
tessellation.
\item
a quadrat test (object of class \code{"quadrattest"})
returned by the command \code{\link{quadrat.test}}.
The quadrats
used to perform the test will be extracted and returned as a
tessellation.
\item
a list of windows (objects of class \code{"owin"})
giving the tiles of the tessellation.
}
The function \code{as.tess} is generic, with methods for
various classes, as listed above.
}
\seealso{
\code{\link{tess}}
}
\examples{
# pixel image
v <- as.im(function(x,y){factor(round(5 * (x^2 + y^2)))}, W=owin())
levels(v) <- letters[seq(length(levels(v)))]
as.tess(v)
# quadrat counts
data(nztrees)
qNZ <- quadratcount(nztrees, nx=4, ny=3)
as.tess(qNZ)
}
\author{Adrian Baddeley
\email{adrian@maths.uwa.edu.au}
\url{http://www.maths.uwa.edu.au/~adrian/}
and Rolf Turner
\email{r.turner@auckland.ac.nz}
}
\keyword{spatial}
\keyword{manip}
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