| % File src/library/grDevices/man/gray.colors.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2012 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{gray.colors} |
| \alias{gray.colors} |
| \alias{grey.colors} |
| \title{Gray Color Palette} |
| \description{ |
| Create a vector of \code{n} gamma-corrected gray colors. |
| } |
| \usage{ |
| gray.colors(n, start = 0.3, end = 0.9, gamma = 2.2, alpha = NULL, rev = FALSE) |
| grey.colors(n, start = 0.3, end = 0.9, gamma = 2.2, alpha = NULL, rev = FALSE) |
| } |
| \arguments{ |
| \item{n}{the number of gray colors (\eqn{\ge 1}) to be in the |
| palette.} |
| \item{start}{starting gray level in the palette (should be between |
| \code{0} and \code{1} where zero indicates \code{"black"} and one |
| indicates \code{"white"}).} |
| \item{end}{ending gray level in the palette.} |
| \item{gamma}{the gamma correction.} |
| \item{alpha}{the opacity, is specified.} |
| \item{rev}{logical indicating whether the ordering of the colors should |
| be reversed.} |
| } |
| \details{ |
| The function \code{gray.colors} chooses a series of \code{n} |
| gamma-corrected gray levels between \code{start} and \code{end}: |
| \code{seq(start^gamma, end^gamma, length = n)^(1/gamma)}. |
| The returned palette contains the corresponding gray colors. |
| This palette is used in \code{\link{barplot.default}}. |
| |
| \code{grey.colors} is an alias for \code{gray.colors}. |
| } |
| \value{ |
| A vector of \code{n} gray colors. |
| } |
| \seealso{ |
| \code{\link{gray}}, |
| \code{\link{rainbow}}, |
| \code{\link{palette}}. |
| } |
| \examples{ |
| require(graphics) |
| |
| pie(rep(1, 12), col = gray.colors(12)) |
| barplot(1:12, col = gray.colors(12)) |
| } |
| \keyword{color} |