| palette {grDevices} | R Documentation |
View or manipulate the color palette which is used when a col=
has a numeric index.
palette(value)
value |
an optional character vector. |
The color palette and referring to colors by number (see
e.g. par) was provided for compatibility with S: in R
it is almost always better to specify colours by name.
If value has length 1, it is taken to be the name of a built-in
color palette (only "default" is built-in currently). If
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 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 dev.copy or
replayPlot is used). The palette is recorded on the
displaylist at the start of each page and when it is changed.
A character vector giving the palette which was in effect.
This is invisible unless the argument is omitted.
colors for the vector of built-in named colors;
hsv, gray, rainbow,
terrain.colors, ... to construct colors.
adjustcolor, e.g., for tweaking existing palettes;
colorRamp to interpolate colors, making custom palettes;
col2rgb for translating colors to RGB 3-vectors.
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")