Type: Package
Title: Generate Color Mapping Functions
Version: 0.1.0
Date: 2022-12-21
Description: A color mapping is generated according to the break values and corresponding colors. Other colors are generated by interpolating in a certain color space. The functions were part of the 'circlize' package https://CRAN.R-project.org/package=circlize.
Depends: R (> 3.0.0)
Imports: colorspace, grDevices, methods, stats
Suggests: knitr
VignetteBuilder: knitr
URL: https://github.com/jokergoo/colorRamp2
License: MIT + file LICENSE
NeedsCompilation: no
Packaged: 2022-12-21 16:27:28 UTC; guz
Author: Zuguang Gu ORCID iD [aut, cre]
Maintainer: Zuguang Gu <z.gu@dkfz.de>
Repository: CRAN
Date/Publication: 2022-12-21 16:50:02 UTC

Add transparency to colors

Description

Add transparency to colors

Usage

add_transparency(col, transparency = 0)

Arguments

col

A vector of colors.

transparency

Transparency, numeric value between 0 and 1.

Value

A vector of colors.

Examples

add_transparency("red", 0.5)
add_transparency(1, 0.5)
add_transparency("#FF000080", 0.2)

Convert back from colors to values

Description

Convert back from colors to values

Usage

col2value(r, g, b, col_fun)

Arguments

r

Red channel in sRGB color space. Value should be between 0 and 1. The value can also be a character vector of colors or a three-column matrix with r, g, b as columns. In this case, g and b are ignored,

g

Green channel in sRGB color space. Value should be between 0 and 1.

b

Blue channel in sRGB color space. Value should be between 0 and 1.

col_fun

the color mapping function generated by colorRamp2.

Details

colorRamp2 maps values to colors and this function does the reversed job. Note for some color spaces, it cannot convert back to the original value perfectly.

Value

A vector of original numeric values.

Author(s)

Zuguang Gu <z.gu@dkfz.de>

Examples

x = seq(0, 1, length.out = 11)
col_fun = colorRamp2(c(0, 0.5, 1), c("blue", "white", "red"))
col = col_fun(x)
col2value(col, col_fun = col_fun)
col2value("red", col_fun = col_fun)

col_fun = colorRamp2(c(0, 0.5, 1), c("blue", "white", "red"), space = "sRGB")
col = col_fun(x)
col2value(col, col_fun = col_fun)

Generate color mapping functions

Description

Generate color mapping functions

Usage

colorRamp2(breaks, colors, transparency = 0, space = "LAB",
    hcl_palette = NULL, reverse = FALSE)

Arguments

breaks

A vector of numeric break values.

colors

A vector of colors which correspond to values in breaks.

transparency

A single value in [0, 1]. 0 refers to no transparency and 1 refers to full transparency.

space

Color space in which colors are interpolated. Value should be one of "RGB", "LAB", "XYZ", "sRGB", "LUV", see color-class for details.

hcl_palette

Name of the HCL palette. Value should be supported in hcl.pals.

reverse

Whether should the colors in hcl_palette be reversed.

Details

Colors are linearly interpolated according to the break values and corresponding colors through a certain color space. Values exceeding breaks will be assigned with corresponding maximum or minimum colors.

Value

A function which accepts a vector of numeric values and returns interpolated colors.

See Also

col2value converts back to the original values by providing the color mapping function generated by colorRamp2.

Examples

col_fun = colorRamp2(c(-1, 0, 1), c("green", "white", "red"))
col_fun(c(-2, -1, -0.5, 0, 0.5, 1, 2))

Generate random colors

Description

Generate random colors

Usage

rand_color(n, hue = NULL, luminosity = "random", transparency = 0, friendly = FALSE)

Arguments

n

Number of colors

hue

The hue of the generated color. You can use following default color name: red, orange, yellow, green, blue, purple, pink and monochrome. If the value is a hexidecimal color string such as #00FFFF, the function will extract its hue value and use that to generate colors.

luminosity

it controls the luminosity of the generated color. The value should be a string containing bright, light, dark and random.

transparency

Transparency, numeric value between 0 and 1.

friendly

If it is true, light random colors will not be generated.

Details

The code is adapted from randomColor.js (https://github.com/davidmerfield/randomColor ).

Value

A vector of colors.

Author(s)

Zuguang Gu <z.gu@dkfz.de>

Examples

plot(NULL, xlim = c(1, 10), ylim = c(1, 8), axes = FALSE, ann = FALSE)
points(1:10, rep(1, 10), pch = 16, cex = 5, 
    col = rand_color(10))
points(1:10, rep(2, 10), pch = 16, cex = 5, 
    col = rand_color(10, luminosity = "bright"))
points(1:10, rep(3, 10), pch = 16, cex = 5, 
    col = rand_color(10, luminosity = "light"))
points(1:10, rep(4, 10), pch = 16, cex = 5, 
    col = rand_color(10, luminosity = "dark"))
points(1:10, rep(5, 10), pch = 16, cex = 5, 
    col = rand_color(10, hue = "red", luminosity = "bright"))
points(1:10, rep(6, 10), pch = 16, cex = 5, 
    col = rand_color(10, hue = "green", luminosity = "bright"))
points(1:10, rep(7, 10), pch = 16, cex = 5, 
    col = rand_color(10, hue = "blue", luminosity = "bright"))
points(1:10, rep(8, 10), pch = 16, cex = 5, 
    col = rand_color(10, hue = "monochrome", luminosity = "bright"))