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\name{Extract.linnet}
\alias{[.linnet}
\title{Extract Subset of Linear Network}
\description{
Extract a subset of a linear network.
}
\usage{
\method{[}{linnet}(x, i, \dots, snip=TRUE)
}
\arguments{
\item{x}{
A linear network (object of class \code{"linnet"}).
}
\item{i}{
Spatial window defining the subregion.
An object of class \code{"owin"}.
}
\item{snip}{
Logical. If \code{TRUE} (the default), segments of \code{x}
which cross the boundary of \code{i} will be cut by the boundary.
If \code{FALSE}, these segments will be deleted.
}
\item{\dots}{Ignored.}
}
\value{
Another linear network (object of class \code{"linnet"}).
}
\details{
This function computes the intersection
between the linear network \code{x} and the domain specified by \code{i}.
This function is a method for the subset operator \code{"["} for
linear networks (objects of class \code{"linnet"}). It is provided
mainly for completeness.
The index \code{i} should be a window.
The argument \code{snip} specifies what to do with segments of \code{x}
which cross the boundary of \code{i}.
If \code{snip=FALSE}, such segments are simply deleted.
If \code{snip=TRUE} (the default), such segments are cut into pieces by the
boundary of \code{i}, and those pieces which lie inside the window
\code{i} are included in the resulting network.
}
\examples{
p <- par(mfrow=c(1,2), mar=0.2+c(0,0,1,0))
B <- owin(c(0.1,0.7),c(0.19,0.6))
plot(simplenet, main="x[w, snip=TRUE]")
plot(simplenet[B], add=TRUE, col="green", lwd=3)
plot(B, add=TRUE, border="red", lty=3)
plot(simplenet, main="x[w, snip=FALSE]")
plot(simplenet[B, snip=FALSE], add=TRUE, col="green", lwd=3)
plot(B, add=TRUE, border="red", lty=3)
par(p)
}
\author{
\adrian,
\rolf,
\ege
and Suman Rakshit.
}
\keyword{spatial}
\keyword{manip}
\concept{Linear network}
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