Revision 9fc33b4ac23fdcf8e2e93aacb1e9fc5842d57bf3 authored by Adrian Baddeley on 18 December 2007, 00:00:00 UTC, committed by Gabor Csardi on 18 December 2007, 00:00:00 UTC
1 parent 6db367d
rescale.psp.Rd
\name{rescale.psp}
\alias{rescale.psp}
\title{Convert Line Segment Pattern to Another Unit of Length}
\description{
Converts a line segment pattern dataset to
another unit of length.
}
\usage{
\method{rescale}{psp}(X, s)
}
\arguments{
\item{X}{Line segment pattern (object of class \code{"psp"}).}
\item{s}{Conversion factor: the new units are \code{s} times the old units.}
}
\value{
Another line segment pattern (of class \code{"psp"}),
representing the same data, but expressed in the new units.
}
\details{
This is a method for the generic function \code{\link{rescale}}.
The spatial coordinates in the line segment pattern \code{X}
(and its window) will be re-expressed
in terms of a new unit of length that is \code{s} times the current
unit of length given in \code{X}.
(Thus, the coordinate values are \emph{divided} by \code{s},
while the unit value is multiplied by \code{s}).
The result is a line segment pattern representing the \emph{same} data
but re-expressed in a different unit.
Mark values are unchanged.
}
\section{Note}{
The result of this operation is equivalent to the original segment pattern.
If you want to actually change the coordinates by
a linear transformation, producing a segment pattern that is not
equivalent to the original one, use \code{\link{affine}}.
}
\seealso{
\code{\link{units}},
\code{\link{affine}},
\code{\link{rotate}},
\code{\link{shift}}
}
\examples{
data(copper)
X <- copper$Lines
X
# data are in km
# convert to metres
rescale(X, 1/1000)
}
\author{Adrian Baddeley
\email{adrian@maths.uwa.edu.au}
\url{http://www.maths.uwa.edu.au/~adrian/}
and Rolf Turner
\email{rolf@math.unb.ca}
\url{http://www.math.unb.ca/~rolf}
}
\keyword{spatial}
\keyword{math}
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