get_brewer_pal: Get and plot a (modified) Color Brewer palette (deprecated)

Description

Get and plot a (modified) palette from Color Brewer. This function is deprecated. Please use c4a instead.

Usage

get_brewer_pal(palette, n = 5, contrast = NA, stretch = TRUE, plot = TRUE)

Value

vector of color values. It is silently returned when plot=TRUE.

Arguments

palette: name of the color brewer palette. Run palette_explorer or see brewer.pal for options.
n: number of colors
contrast: a vector of two numbers between 0 and 1 that defines the contrast range of the palette. Applicable to sequential and diverging palettes. For sequential palettes, 0 stands for the leftmost color and 1 the rightmost color. For instance, when contrast=c(.25, .75), then the palette ranges from 1/4 to 3/4 of the available color range. For diverging palettes, 0 stands for the middle color and 1 for both outer colors. If only one number is provided, the other number is set to 0. The default value depends on n. See details.
stretch: logical that determines whether intermediate colors are used for a categorical palette when n is greater than the number of available colors.
plot: should the palette be plot, or only returned? If TRUE the palette is silently returned.

Details

The default contrast of the palette depends on the number of colors, n, in the following way. The default contrast is maximal, so (0, 1), when n = 9 for sequential palettes and n = 11 for diverging palettes. The default contrast values for smaller values of n can be extracted with some R magic: sapply(1:9, tmaptools:::default_contrast_seq) for sequential palettes and sapply(1:11, tmaptools:::default_contrast_div) for diverging palettes.

Examples

Run this code

get_brewer_pal("Blues")
get_brewer_pal("Blues", contrast=c(.4, .8))
get_brewer_pal("Blues", contrast=c(0, 1))
get_brewer_pal("Blues", n=15, contrast=c(0, 1))

get_brewer_pal("RdYlGn")
get_brewer_pal("RdYlGn", n=11)
get_brewer_pal("RdYlGn", n=11, contrast=c(0, .4))
get_brewer_pal("RdYlGn", n=11, contrast=c(.4, 1))

get_brewer_pal("Set2", n = 12)
get_brewer_pal("Set2", n = 12, stretch = FALSE)