Silvia Canelón

Our illustrated penguins have reached the purrr package! The photo backdrop is a snowy Antarctic wonderland featuring a Gentoo penguin with outstretched flippers

Photo by James Eades on Unsplash

purrr: info

Provides tools for working with functions and vectors

The purrr family of functions helps us replace for loops, making our code easier to read and more succint.

With `purrr` you can

Iterate over a single input with map()
Iterate over two inputs in parallel with map2()
Iterate with multiple arguments with pmap()
Iterate with multiple arguments and functions with invoke_map()
Call a function for its side-effects with walk(), walk2(), and pwalk()

purrr: exercise

Ok, we love our earlier boxplot showing us body_mass_g by sex and colored by species…

…but let’s change up the colors to keep with our Antarctica theme!

I’m a big fan of the color palettes in the nord 📦

16 different nordic color palettes from the Nord package. We will be focusing on the mountain_forms palette which was dark teal, dusty blue, snowy white, dusty purple, and dark purple

You can choose colors using
the color hex codes

nord::nord_palettes$mountain_forms

[1] "#184860" "#486078" "#d8d8d8" "#484860" "#181830"

And assign them using the scale_fill_manual() function

penguins |>
  ggplot(aes(x = sex, y = body_mass_g)) +
  geom_boxplot(aes(fill = species)) +
  scale_fill_manual(
    values = c("#184860", 
               "#D8D8D8", 
               "#181830"))

You can also use the palette name, like mountain_forms, though the colors assigned may not align with what you want

penguins |>
  ggplot(aes(x = sex, y = body_mass_g)) +
  geom_boxplot(aes(fill = species)) +
  scale_fill_manual(
    values = nord::nord_palettes$mountain_forms
    )

Our boxplot filled with nordic colors though the scale_fill_manual function has automatically selected a different combination of colors from the palette. Gentoo boxplots are snowy white intead of dark purple, Adélie boxplots are a still a dark teal, and Chinstrap boxplots are a dusty blue intead of snowy white.

And sometimes, color palette packages come with their own functions that assign colors, like scale_fill_nord()

penguins |>
  ggplot(aes(x = sex, y = body_mass_g)) +
  geom_boxplot(aes(fill = species)) +
  nord::scale_fill_nord(
    palette = "mountain_forms"
    )

Our boxplot filled with nordic colors. Gentoo boxplots are a dark purple, Adélie boxplots are a dark teal, and Chinstrap boxplots are a snowy white.

The prismatic 📦 helps us see the colors that correspond to each color hex code (mostly), with the color() function

library(prismatic)

prismatic::color(
    nord::nord_palettes$mountain_forms
    )

hex codes for the 5 colors in the mountain_forms palette, with a background color to match it. Dark teal is #184860, dusty blue is #486078, snowy white is #D8D8D8, purple is #484860, and dark purple is #181830

purrr’s map() function can help us iterate color() over all palettes in a palette package like nord!

nord::nord_palettes |> 
    map(prismatic::color)

hex color codes for 4 of the palettes in the nord package, including mountain_forms

purrr: info

Provides tools for working with functions and vectors

With `purrr` you can

R for Data Science: Ch 21 Iteration

Package documentation: https://purrr.tidyverse.org

purrr: exercise