\name{plot.ssf}
\alias{plot.ssf}
\alias{image.ssf}
\alias{contour.ssf}
\title{
Plot a Spatially Sampled Function
}
\description{
Plot a spatially sampled function object.
}
\usage{
\method{plot}{ssf}(x, \dots,
how = c("smoothed", "nearest", "points"),
style = c("image", "contour", "imagecontour"),
sigma = NULL, contourargs=list())
\method{image}{ssf}(x, \dots)
\method{contour}{ssf}(x, ..., main, sigma = NULL)
}
\arguments{
\item{x}{
Spatially sampled function (object of class \code{"ssf"}).
}
\item{\dots}{
Arguments passed to \code{\link[graphics]{image.default}}
or
\code{\link[spatstat]{plot.ppp}} to control the plot.
}
\item{how}{
Character string determining whether to display the
function values at the data points (\code{how="points"}),
a smoothed interpolation of the function
(\code{how="smoothed"}), or the function value at the
nearest data point (\code{how="nearest"}).
}
\item{style}{
Character string indicating whether to plot the smoothed function as
a colour image, a contour map, or both.
}
\item{contourargs}{
Arguments passed to \code{\link[graphics]{contour.default}}
to control the contours, if \code{style="contour"} or
\code{style="imagecontour"}.
}
\item{sigma}{
Smoothing bandwidth for smooth interpolation.
}
\item{main}{
Optional main title for the plot.
}
}
\details{
These are methods for the generic
\code{\link[graphics]{plot}},
\code{\link[graphics]{image}} and
\code{\link[graphics]{contour}}
for the class \code{"ssf"}.
An object of class \code{"ssf"} represents a
function (real- or vector-valued) that has been
sampled at a finite set of points.
For \code{plot.ssf} there are three types of display.
If \code{how="points"} the exact function values
will be displayed as circles centred at the locations where they
were computed. If \code{how="smoothed"} (the default) these
values will be kernel-smoothed using \code{\link{smooth.ppp}}
and displayed as a pixel image.
If \code{how="nearest"} the values will be interpolated
by nearest neighbour interpolation using \code{\link{nnmark}}
and displayed as a pixel image.
For \code{image.ssf} and \code{contour.ssf} the values are
kernel-smoothed before being displayed.
}
\value{
\code{NULL}.
}
\references{
Baddeley, A. (2016)
Local composite likelihood for spatial point processes.
Submitted for publication.
Baddeley, A., Rubak, E. and Turner, R. (2015)
\emph{Spatial Point Patterns: Methodology and Applications with R}.
Chapman and Hall/CRC Press.
}
\author{
\adrian.
}
\seealso{
\code{\link{ssf}}
}
\examples{
a <- ssf(cells, nndist(cells, k=1:3))
plot(a, how="points")
plot(a, how="smoothed")
plot(a, how="nearest")
}
\keyword{spatial}
\keyword{hplot}