colour_values

0th

Percentile

Colour Values

maps colours to values

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

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

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

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

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

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

# S3 method for POSIXct colour_values_to_hex( x, palette, alpha, na_colour, 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

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.

na_colour

hex string colour to use for NA values in the form #RRGGBBAA.

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

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.

See Also

colour_values_rgb

Aliases
  • colour_values
  • color_values
  • colour_values_to_hex.character
  • colour_values_to_hex.logical
  • colour_values_to_hex.factor
  • colour_values_to_hex.Date
  • colour_values_to_hex.POSIXct
  • colour_values_to_hex.POSIXlt
Examples
# NOT RUN {
## in-built palettes
colour_values(x = 1:5) ## default is "viridis"
colour_values(x = 1:5, palette = "inferno")
colour_values(x = 1:5, palette = "plasma")
colour_values(x = 1:5, palette = "magma")
colour_values(x = 1:5, palette = "cividis")
colour_values(x = 1:5, palette = "rainbow")

## 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)

# }
Documentation reproduced from package colourvalues, version 0.3.6, License: GPL-3

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