Colour Values

maps colours to values

colour_values(x, palette = "viridis", na_colour = "#808080FF",
  alpha = 255, include_alpha = TRUE, ...)

color_values(x, palette = "viridis", na_colour = "#808080FF",
  alpha = 255, include_alpha = TRUE, ...)

# S3 method for character
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, summary = FALSE)

# S3 method for default
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, n_summaries = 0, format = TRUE, digits = 2)

# S3 method for logical
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, summary = FALSE)

# S3 method for factor
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, summary = FALSE)

# S3 method for Date
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, n_summaries = 0, format = TRUE)

# S3 method for POSIXct
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, n_summaries = 0, format = TRUE)

# S3 method for POSIXlt
colour_values_to_hex(x, palette, na_colour, alpha,
  include_alpha, n_summaries = 0, format = TRUE)

Arguments

x	vector of values to map to a colour
palette	colour palette. See details and examples
na_colour	hex string colour to use for NA values in the form #RRGGBBAA.
alpha	optional. Single value in [0,255] applied to all colours, or a decimal in [0, 1) (to indicate a percentage, noting 1 is excluded), or a vector of numeric values the same length as x. The numeric vector will be scaled into the range [0,255]. If a matrix palette is supplied this argument is ignored.
include_alpha	logical indicating if the returned hex or matrix should include the alpha values. Defaults to TRUE.
...	other arguments possed to methods
summary	logical indicating if a summary of the colours should be returned as well as the full colour mapping. This will be the unique elements of x mapped to the colour.
n_summaries	positive integer. If supplied a summary colour palette will be returned in a list, containing n_summaries equally spaced values of x in the range [min(x),max(x)], and their associated colours. If a non-numeric x is used this value is ignored
format	logical indicating if the summary values should be formatted. See details
digits	Integer. When summarising a numeric vector you can specify the number of decimal places to include in the summary values

Details

The palette can either be

• String - use colour_palettes() to view available palettes

• Matrix - At least 5 rows, and 3 (or 4) columns representing the red, green and blue (and alpha) values

The matrix palette requires 5 rows because the colours are interpolated using a cubic b-spline. This method requires 5 values.

when summary = TRUE, the following rules are applied to the summary values

• logical vectors are converted to "TRUE" or "FALSE" strings

• all other types remain as-is, unless format = T is used

when format = TRUE,

• numbers are converted to strings with the specified number of decimal places (using digits argument)

• Dates are formatted as "yyyy-mm-dd"

See also

colour_values_rgb

Examples

## in-built palettes
colour_values(x = 1:5) ## default is "viridis"
#> [1] "#440154FF" "#3B528BFF" "#21908CFF" "#5DC963FF" "#FDE725FF"
colour_values(x = 1:5, palette = "inferno")
#> [1] "#000004FF" "#57106DFF" "#BB3755FF" "#F98D0AFF" "#FCFFA4FF"
colour_values(x = 1:5, palette = "plasma")
#> [1] "#0D0887FF" "#7E03A8FF" "#CB4778FF" "#F89441FF" "#F0F921FF"
colour_values(x = 1:5, palette = "magma")
#> [1] "#000004FF" "#50127CFF" "#B63779FF" "#FB8761FF" "#FCFDBFFF"
colour_values(x = 1:5, palette = "cividis")
#> [1] "#00204DFF" "#414D6BFF" "#7C7B78FF" "#BDAF6FFF" "#FFEA46FF"
colour_values(x = 1:5, palette = "rainbow")
#> [1] "#FF0000FF" "#81FF00FF" "#00FFFCFF" "#7C00FFFF" "#FF0006FF"

## matrix palette
n <- 100
m <- grDevices::colorRamp(c("red", "green"))( (1:n)/n )
df <- data.frame(a = 10, x = 1:n)
df$col <- colour_values(df$x, palette = m)
barplot(height = df$a, col = df$col, border = NA, space = 0)

## with an alpha column on the palette
n <- 100
m <- grDevices::colorRamp(c("red", "green"))( (1:n)/n )
m <- cbind(m, seq(0, 255, length.out = 100))
df <- data.frame(a = 10, x = 1:n)
df$col <- colour_values(df$x, palette = m)
barplot(height = df$a, col = df$col, border = NA, space = 0)

## single alpha value for all colours
df <- data.frame(a = 10, x = 1:255)
df$col <- colour_values(df$x, alpha = 50)
barplot(height = df$a, col = df$col, border = NA, space = 0)

## vector of alpha values
df <- data.frame(a = 10, x = 1:300, y = rep(c(1:50, 50:1), 3) )
df$col <- colour_values(df$x, alpha = df$y)
barplot(height = df$a, col = df$col, border = NA, space = 0)

## returning a summary palette
colour_values(-10:10, n_summaries = 5)
#> $colours
#>  [1] "#440154FF" "#481466FF" "#482575FF" "#463480FF" "#414487FF" "#3B528BFF"
#>  [7] "#345F8DFF" "#2F6C8EFF" "#2A788EFF" "#25848EFF" "#21908CFF" "#1E9C89FF"
#> [13] "#22A884FF" "#2FB47CFF" "#43BF71FF" "#5DC963FF" "#7AD151FF" "#9AD93DFF"
#> [19] "#BCDF27FF" "#DDE318FF" "#FDE725FF"
#> 
#> $summary_values
#> [1] "-10.00" "-5.00"  "0.00"   "5.00"   "10.00" 
#> 
#> $summary_colours
#> [1] "#440154FF" "#3B528BFF" "#21908CFF" "#5DC963FF" "#FDE725FF"
#>