XGR (version 1.1.4)

xColormap: Function to define a colormap

Description

xColormap is supposed to define a colormap. It returns a function, which will take an integer argument specifying how many colors interpolate the given colormap.

Usage

xColormap(colormap = c("bwr", "jet", "gbr", "wyr", "br", "yr",
"rainbow",
"wb", "heat", "terrain", "topo", "cm", "ggplot2", "jet.top",
"jet.bottom",
"jet.both", "spectral", "ggplot2.top", "ggplot2.bottom",
"ggplot2.both",
"RdYlBu"), interpolate = c("spline", "linear"))

Arguments

colormap

short name for the colormap. It can be one of "jet" (jet colormap), "bwr" (blue-white-red colormap), "gbr" (green-black-red colormap), "wyr" (white-yellow-red colormap), "br" (black-red colormap), "yr" (yellow-red colormap), "wb" (white-black colormap), "rainbow" (rainbow colormap, that is, red-yellow-green-cyan-blue-magenta), and "ggplot2" (emulating ggplot2 default color palette). Alternatively, any hyphen-separated HTML color names, e.g. "lightyellow-orange" (by default), "blue-black-yellow", "royalblue-white-sandybrown", "darkgreen-white-darkviolet". A list of standard color names can be found in http://html-color-codes.info/color-names. It can also be a function of 'colorRampPalette'

interpolate

use spline or linear interpolation

Value

• palette.name: a function that takes an integer argument for generating that number of colors interpolating the given sequence

Examples

# NOT RUN {
# 1) define "blue-white-red" colormap
palette.name <- xColormap(colormap="bwr")
# use the return function "palette.name" to generate 10 colors spanning "bwr"
palette.name(10)

# 2) define default colormap from ggplot2
palette.name <- xColormap(colormap="ggplot2")
# use the return function "palette.name" to generate 3 default colors used by ggplot2
palette.name(3)

# 3) define brewer colormap called "RdYlBu"
palette.name <- xColormap(colormap="RdYlBu")
# use the return function "palette.name" to generate 3 default colors used by ggplot2
palette.name(3)
# }