https://github.com/cran/spatstat
Tip revision: 2910896e7be42bade87fb5b17a6239f86cb05760 authored by Adrian Baddeley on 15 June 2018, 06:48:03 UTC
version 1.56-0
version 1.56-0
Tip revision: 2910896
cut.im.Rd
\name{cut.im}
\alias{cut.im}
\title{Convert Pixel Image from Numeric to Factor}
\description{
Transform the values of a pixel image
from numeric values into a factor.
}
\usage{
\method{cut}{im}(x, \dots)
}
\arguments{
\item{x}{
A pixel image.
An object of class \code{"im"}.
}
\item{\dots}{
Arguments passed to \code{\link{cut.default}}.
They determine the breakpoints for the mapping from numerical values to
factor values. See \code{\link{cut.default}}.
}
}
\value{
A pixel image (object of class \code{"im"}) with
pixel values that are a factor.
See \code{\link{im.object}}.
}
\details{
This simple function applies the generic \code{\link{cut}} operation
to the pixel values of the image \code{x}. The range of pixel values
is divided into several intervals, and each
interval is associated with a level of a factor.
The result is another pixel image,
with the same window and pixel grid as
\code{x}, but with the numeric value of each pixel discretised
by replacing it by the factor level.
This function is a convenient
way to inspect an image and to obtain summary statistics.
See the examples.
To select a subset of an image, use the subset operator
\code{\link{[.im}} instead.
}
\seealso{
\code{\link{cut}},
\code{\link{im.object}}
}
\examples{
# artificial image data
Z <- setcov(square(1))
Y <- cut(Z, 3)
Y <- cut(Z, breaks=seq(0,1,length=5))
# cut at the quartiles
# (divides the image into 4 equal areas)
Y <- cut(Z, quantile(Z))
}
\author{\adrian
and \rolf
}
\keyword{spatial}
\keyword{methods}