| % File src/library/grDevices/man/palette.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2015 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{palette} |
| \title{Set or View the Graphics Palette} |
| \usage{ |
| palette(value) |
| } |
| \alias{palette} |
| \arguments{ |
| \item{value}{an optional character vector.} |
| } |
| \description{ |
| View or manipulate the color palette which is used when a \code{col=} |
| has a numeric index. |
| } |
| \details{ |
| The color palette and referring to colors by number (see |
| e.g.\sspace{}\code{\link{par}}) was provided for compatibility with S: in \R |
| it is almost always better to specify colours by name. |
| |
| If \code{value} has length 1, it is taken to be the name of a built-in |
| color palette (only \code{"default"} is built-in currently). If |
| \code{value} has length greater than 1 it is assumed to contain a |
| description of the colors which are to make up the new palette (either |
| by name or by RGB levels). The maximum size for a palette is 1024 |
| entries. |
| |
| If \code{value} is omitted, no change is made to the current palette. |
| |
| There is only one palette setting for all devices in a \R session. If |
| the palette is changed, the new palette applies to all subsequent |
| plotting. |
| |
| The current palette also applies to re-plotting (for example if an |
| on-screen device is resized or \code{\link{dev.copy}} or |
| \code{\link{replayPlot}} is used). The palette is recorded on the |
| displaylist at the start of each page and when it is changed. |
| } |
| |
| \value{ |
| A character vector giving the palette which \emph{was} in effect. |
| This is \code{\link{invisible}} unless the argument is omitted. |
| } |
| \seealso{ |
| \code{\link{colors}} for the vector of built-in named colors; |
| \code{\link{hsv}}, \code{\link{gray}}, \code{\link{rainbow}}, |
| \code{\link{terrain.colors}}, \dots to construct colors. |
| |
| \code{\link{adjustcolor}}, e.g., for tweaking existing palettes; |
| \code{\link{colorRamp}} to interpolate colors, making custom palettes; |
| \code{\link{col2rgb}} for translating colors to RGB 3-vectors. |
| } |
| \examples{ |
| require(graphics) |
| |
| palette() # obtain the current palette |
| palette(rainbow(6)) # six color rainbow |
| |
| (palette(gray(seq(0,.9,len = 25)))) # gray scales; print old palette |
| matplot(outer(1:100, 1:30), type = "l", lty = 1,lwd = 2, col = 1:30, |
| main = "Gray Scales Palette", |
| sub = "palette(gray(seq(0, .9, len=25)))") |
| palette("default") # reset back to the default |
| |
| ## on a device where alpha-transparency is supported, |
| ## use 'alpha = 0.3' transparency with the default palette : |
| mycols <- adjustcolor(palette(), alpha.f = 0.3) |
| opal <- palette(mycols) |
| x <- rnorm(1000); xy <- cbind(x, 3*x + rnorm(1000)) |
| plot (xy, lwd = 2, |
| main = "Alpha-Transparency Palette\n alpha = 0.3") |
| xy[,1] <- -xy[,1] |
| points(xy, col = 8, pch = 16, cex = 1.5) |
| palette("default") |
| } |
| \keyword{color} |
| \keyword{sysdata} |