RColorBrewer: ColorBrewer palettes

Description

Creates nice looking color palettes especially for thematic maps

Usage

brewer.pal(n, name)
display.brewer.pal(n, name)
display.brewer.all(n=NULL, type="all", select=NULL, exact.n=TRUE, 
colorblindFriendly=FALSE)
brewer.pal.info

Arguments

Number of different colors in the palette, minimum 3, maximum depending on palette

name

A palette name from the lists below

type

One of the string "div", "qual", "seq", or "all"

select

A list of names of existing palettes

exact.n

If TRUE, only display palettes with a color number given by n

colorblindFriendly

if TRUE, display only colorblind friendly palettes

Value

A palette

You will get an error when you ask for a nonexisting palette, and you will get a warning if a palette you asked for exists but not with as many different leves as you asked for.

Details

brewer.pal makes the color palettes from ColorBrewer available as R palettes.

display.brewer.pal() displays the selected palette in a graphics window.

display.brewer.all() displays the a few palettes simultanueously in a graphics window.

brewer.pal.info returns information about the available palettes as a dataframe. brewer.pal.info is not a function, it is a variable. This might change in the future.

For details and an interactive palette selection tools see http://colorbrewer.org. It is free to use, although ColorBrewer's designers would appreciate it if you could cite the ColorBrewer project if you decide to use one of our color schemes.

There are 3 types of palettes, sequential, diverging, and qualitative.

1. Sequential palettes are suited to ordered data that progress from low to high. Lightness steps dominate the look of these schemes, with light colors for low data values to dark colors for high data values.

2. Diverging palettes put equal emphasis on mid-range critical values and extremes at both ends of the data range. The critical class or break in the middle of the legend is emphasized with light colors and low and high extremes are emphasized with dark colors that have contrasting hues.

3. Qualitative palettes do not imply magnitude differences between legend classes, and hues are used to create the primary visual differences between classes. Qualitative schemes are best suited to representing nominal or categorical data.

The sequential palettes names are

Blues BuGn BuPu GnBu Greens Greys Oranges OrRd PuBu PuBuGn PuRd Purples RdPu Reds YlGn YlGnBu YlOrBr YlOrRd

All the sequential palettes are available in variations from 3 different values up to 9 different values.

The diverging palettes are BrBG PiYG PRGn PuOr RdBu RdGy RdYlBu RdYlGn Spectral

All the diverging palettes are available in variations from 3 different values up to 11 different values.

For qualitative palettes, the lowest number of distinct values available always is 3, but the largest number is different for different palettes. It is given together with the palette names in the following table.

Accent	8
Dark2	8
Paired	12
Pastel1	9
Pastel2	8
Set1	9
Set2	8

The ColorBrewer palettes have been included in this R package with permission of the copyright holder.

For license details see the file COPYING included in this package.

Examples

Run this code

# NOT RUN {
## create a sequential palette for usage and show colors
mypalette<-brewer.pal(7,"Greens")
image(1:7,1,as.matrix(1:7),col=mypalette,xlab="Greens (sequential)",
       ylab="",xaxt="n",yaxt="n",bty="n")
## display a divergent palette
display.brewer.pal(7,"BrBG")
devAskNewPage(ask=TRUE)
## display a qualitative palette
display.brewer.pal(7,"Accent")
devAskNewPage(ask=TRUE)
## display a palettes simultanoeusly
display.brewer.all(n=10, exact.n=FALSE)
devAskNewPage(ask=TRUE)
display.brewer.all(n=10)
devAskNewPage(ask=TRUE)
display.brewer.all()
devAskNewPage(ask=TRUE)
display.brewer.all(type="div")
devAskNewPage(ask=TRUE)
display.brewer.all(type="seq")
devAskNewPage(ask=TRUE)
display.brewer.all(type="qual") 
devAskNewPage(ask=TRUE)
display.brewer.all(n=5,type="div",exact.n=TRUE)
devAskNewPage(ask=TRUE)
display.brewer.all(colorblindFriendly=TRUE)
devAskNewPage(ask=TRUE)
brewer.pal.info
brewer.pal.info["Blues",]
brewer.pal.info["Blues",]$maxcolors
# }