https://github.com/cran/lattice
Tip revision: c58bc88dad1b19b30564fa9e357181cb09c953c3 authored by Deepayan Sarkar on 16 May 2008, 00:00:00 UTC
version 0.17-8
version 0.17-8
Tip revision: c58bc88
level.colors.Rd
\name{level.colors}
\alias{level.colors}
\title{
A function to compute false colors representing a numeric or
categorical variable
}
\description{
Calculates false colors from a numeric variable (including factors,
using their numeric codes) given a color scheme and breakpoints.
}
\usage{
level.colors(x, at, col.regions, colors = TRUE, ...)
}
\arguments{
\item{x}{ A numeric or \code{\link{factor}} variable }
\item{at}{ A numeric variable of breakpoints where colors change }
\item{col.regions}{ A specification of the colors to be used. This
could be either a vector of colors, or a function that produces a
vector of colors when called with a single argument giving the
number of colors. }
\item{colors}{ logical indicating whether colors should be computed
and returned. If \code{FALSE}, only the indices representing which
interval (among those defined by \code{at}) each value in \code{x}
falls into is returned. }
\item{\dots}{ Extra arguments, ignored. }
}
\value{
A vector of the same length as \code{x}. Depending on the
\code{colors} argument, this could be either a vector of colors (in
a form usable by \R), or a vector of integer indices representing
which interval the values of \code{x} fall in.
}
\author{ Deepayan Sarkar \email{deepayan.sarkar@r-project.org} }
\seealso{ \code{\link{levelplot}} }
\examples{
depth.col <-
with(quakes,
level.colors(depth, at = do.breaks(range(depth), 30),
col.regions = terrain.colors))
xyplot(lat ~ long | equal.count(stations), quakes,
strip = strip.custom(var.name = "Stations"),
colours = depth.col,
panel = function(x, y, colours, subscripts, ...) {
panel.xyplot(x, y, pch = 21, col = "transparent",
fill = colours[subscripts], ...)
})
}
\keyword{utilities}