In ab604/sotoncolours: University of Southampton colour palettes

knitr::opts_chunk$set(echo = TRUE)
library(sotoncolours)

University of Southampton Colour Palettes

sotoncolours provides colour palettes for use with plot or ggplot2 based upon the University of Southampton colour palettes of neutral, marine, horizon and web.

The code is largely re-purposed from the ochRe package

It has two functions for use with ggplot2, either as discrete colours or gradients:

scale_fill_uos()
scale_colour_uos()

and the palettes or specific colours can be called using uos_cols() and/or uos_colours. Colours can be used in the base plotting functions too.

See examples below and more details in the vignette.

Installation

Use can install from github using devtools. Run install.packages("devtools") if necessary first.

devtools::install_github("ab604/sotoncolours", build_vignettes = TRUE)

vignette("sotoncolours")

and then load the library as usual:

library(sotoncolours)

Colour and palette choices

The package contains 19 colours and 7 colour palettes contained within a named character vector called uos_colours:

# Named character vector of the colours
uos_colours

# See names of all palettes
names(uos_palettes)

The palettes

pal_names <- names(uos_palettes)

par(mfrow=c(length(uos_palettes)/2, 2), lheight = 2, mar=rep(1, 4), adj = 0)
for (i in 1:length(uos_palettes)){
    viz_palette(uos_palettes[[i]], pal_names[i])
}

Example

Here is an example using Alison Horst's Palmer Penguins dataset and ggplot2 and scale_fill_uos()

library(palmerpenguins)
library(ggplot2)

ggplot(data = penguins, aes(x = flipper_length_mm)) +
  geom_histogram(aes(fill = species), 
                 alpha = 0.5, 
                 position = "identity") +
  scale_fill_uos(palette = "contrast1") +
  theme_minimal() +
  labs(x = "Flipper length (mm)",
       y = "Frequency",
       title = "Penguin flipper lengths")

Here is a base R plot using the horizon palette directly via the colorRampPalette() function.

pal <- colorRampPalette(uos_palettes[["horizon"]])
image(volcano, col = pal(20))

Individual palettes can be visualised using the viz_palette function

viz_palette(uos_palettes[["marine"]])

It's possible, but messy, to pick any colour combination from uos_colours, but the syntax requires extracting the hex codes using unname() and subsetting uos_cols using a character vector of the desired colour names.

It may be easier to create an object for any bespoke palette and pass then pass it to the respective ggplot function.

Here's an example with the Palmer penguin data using unname(uos_colours[c("black","shamrock","horizon4")]) as described above by creating a new palette called my_cols that is passed to the values argument of scale_colour_manual().

# Create a new vector of colours to pass to scale_colour manual
# Use unname() to get hex codes from uos_cols()
my_cols <- unname(uos_colours[c("black","shamrock","horizon4")])

ggplot(data = penguins, aes(x = species, y = flipper_length_mm)) +
  geom_boxplot(aes(color = species), width = 0.3, show.legend = FALSE) +
  geom_jitter(aes(color = species), alpha = 0.7, show.legend = FALSE, 
              position = position_jitter(width = 0.2, seed = 0)) +
  scale_colour_manual(values = my_cols) + # pass my_cols to scale_colour_manual
  theme_minimal() +
  labs(x = "Species",
       y = "Flipper length (mm)")