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
rescale.Rd
\name{rescale}
\alias{rescale}
\title{Convert dataset to another unit of length}
\description{
Converts between different units of length
in a spatial dataset, such as a point pattern or a window.
}
\usage{
rescale(X, s)
}
\arguments{
\item{X}{Any suitable dataset representing a two-dimensional
object, such as a point pattern (object of class \code{"ppp"}),
or a window (object of class \code{"owin"}).}
\item{s}{Conversion factor: the new units are \code{s} times the old units.}
}
\value{
Another object of the same type, representing the same
data, but expressed in the new units.
}
\details{
This is generic. Methods are provided for
point patterns (\code{\link{rescale.ppp}})
and windows (\code{\link{rescale.owin}}).
The spatial coordinates in the dataset \code{X} 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}.
For example if \code{X} is a dataset giving coordinates in metres,
then \code{rescale(X,1000)}
will divide the coordinate values by 1000 to obtain coordinates in
kilometres, and the unit name will be changed from \code{"metres"}
to \code{"1000 metres"}.
}
\section{Note}{
The result of this operation is equivalent to the original dataset.
If you want to actually change the coordinates by
a linear transformation, producing a dataset that is not equivalent
to the original one, use \code{\link{affine}}.
}
\seealso{
\code{\link{unitname}},
\code{\link{rescale.ppp}},
\code{\link{rescale.owin}},
\code{\link{affine}},
\code{\link{rotate}},
\code{\link{shift}}
}
\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{math}
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