Set or View the Graphics Palette

Description

View or manipulate the color palette which is used when a col= has a numeric index.

Usage

palette(value)

Arguments

Details

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.

Value

A character vector giving the palette which was in effect. This is invisible unless the argument is omitted.

See Also

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.

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")

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

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Type 'demo()' for some demos, 'help()' for on-line help, or
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> library(grDevices)
> png(filename="/home/ddbj/snapshot/RGM3/R_rel/result/grDevices/palette.Rd_%03d_medium.png", width=480, height=480)
> ### Name: palette
> ### Title: Set or View the Graphics Palette
> ### Aliases: palette
> ### Keywords: color sysdata
> 
> ### ** Examples
> 
> require(graphics)
> 
> palette()               # obtain the current palette
[1] "black"   "red"     "green3"  "blue"    "cyan"    "magenta" "yellow" 
[8] "gray"   
> palette(rainbow(6))     # six color rainbow
> 
> (palette(gray(seq(0,.9,len = 25)))) # gray scales; print old palette
[1] "red"     "yellow"  "green"   "cyan"    "blue"    "magenta"
> 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")
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>