unipalette: A 7 category qualitative palette

In allopole/datacolor: Color for Data Visualization

Description

unipalette() produces qualitative palettes based on a preset 7-color palette optimized for lines, points, bars, etc, on a white background.

Usage

unipalette(colors = NULL, order = "difference")

Arguments

colors	Integer vector or character vector. colors=4 returns the first 4 colors of the default ordering. colors=2:5 returns the colors 2 through 5 of the default ordering. colors=c("red","lightblue","purple") returns the named colors in the order given.
order	Character. "difference", "lightness", or "hybrid". The ordering for the palette (see details).

Value

character vector. A vector of named RGB colors specified as hex color codes (#RRGGBB).

Base palette, in default ordering

#'

red	lightblue	black	green	purple	pink	blue
"#a11c3e"	"#5798d1"	"#252525"	"#319045"	"#5e2b7b"	"#e2908c"	"#226e83"

Palette characteristics

• designed for high contrast against a white background, with good distinction among colors

• colors distinguishable under two most common forms of colorblindness

• colors distinguishable in greyscale for b/w printing

• Good for bar charts, box plots, pies, etc.

• Line should be relatively thick

• Points should be relatively large

The default ordering (order="difference") maximizes differences in hue and lightness between adjacent colors. This aids discrimination of data plotted side by side, and also helps avoid implications that the data is ordinal.

Palette ordering

Two alternate orderings are also provided.

• unipalette(order="lightness") orders the color by increasing perceived lightness: black purple red blue green lightblue pink

• unipalette(order="hybrid") increases the pairwise lightness difference in an otherwise lightness-ordered palette: black red purple green blue pink lightblue

Palette subsets

unipalette(4) returns the first 4 colors of the default ordering. unipalette(2:5) returns the colors 2 through 5 of the default ordering. unipalette(c("red","lightblue","purple")) returns the named colors in the order given.

Examples

## 3 orderings:
difference <- unipalette(); colorbar(difference,dots=TRUE)
lightness <- unipalette(order="lightness"); colorbar(lightness,dots=TRUE)
hybrid <- unipalette(order="hybrid"); colorbar(hybrid,dots=TRUE)

## subsets
subset <- unipalette(4); colorbar(subset,dots=TRUE)

## Sample plot
randomseries <- data.frame(x=1:4, y=runif(4*7), grp=rep(letters[1:7],each=4))
pal <- unipalette()
lattice::xyplot(y~x, group=grp, data=randomseries, type="b", pch=16, lwd=3, col = pal,
       key = list(space = "right", text=list(letters[1:7], lines = list(col=pal, lwd=3)))
       )

allopole/datacolor documentation built on May 4, 2019, 6:39 p.m.