scale_* functions (ggplot2)

In addition to the NMR palettes themselves, paletteNMR contains scale_* functions for use in ggplot2 graphics

Below, two figures with discrete color scales are created using scale_nmr_color_* variants and scale_nmr_fill variants respectively:

iris |> 
  ggplot(aes(Sepal.Length, Petal.Length)) +
  geom_point(aes(colour = Species),
             size = rel(4), alpha = 1/1.2) +
  scale_nmr_color_categorical(pal = "quad",
                              set = "C",
                              reverse = TRUE)


iris |> 
  ggplot(aes(Sepal.Length, Petal.Length)) +
  geom_point(aes(fill = Species),
             shape = 21, size = rel(4), alpha = 1/1.2) +
  scale_nmr_fill_categorical(pal = "quad",
                              set = "C",
                              reverse = TRUE)

Testing cases with more discrete colors (using the airmiles dataset from the datasets pkg)

airmiles |> 
  as.data.frame() |> 
  setNames("miles") |> 
  mutate(yr = time(airmiles) |> 
           parse_date_time("Y")) |> 
  mutate(yr_grp = floor_date(yr, "10 years") |> 
           year() |> factor()) |> 
  ggplot(aes(yr, miles)) +
  geom_point(aes(color = yr_grp),
             size = rel(4), alpha = 1/1.2) +
  labs(x = NULL, y = "Miles traveled",
       color = NULL) +
  scale_x_datetime(date_breaks = "10 years",
                   date_labels = "%Y") +
  scale_y_continuous(labels = unit_format(unit = "k", scale = 1e-3)) +
  scale_nmr_color_categorical(pal = "quad",
                              set = "C",
                              reverse = TRUE)

Continuous values work too!

iris |> 
  ggplot(aes(Sepal.Length, Petal.Length)) +
  geom_point(aes(colour = Petal.Length),
             size = rel(4), alpha = 1/1.2) +
  scale_nmr_color_sequential(set = "GT6",
                             discrete = FALSE,
                             reverse = TRUE) +
  guides(color = "none")


iris |> 
  ggplot(aes(Sepal.Length, Petal.Length)) +
  geom_point(aes(fill = Petal.Length),
             shape = 21, 
             size = rel(4), alpha = 1/1.2) +
  scale_nmr_fill_sequential(set = "GT6",
                            discrete = FALSE,
                            reverse = TRUE) +
  guides(fill = "none")

Take care to specify the right arguments. For example, using scale_nmr_color_sequential assumes a divergent palette (i.e. pal = "diverg"), so it only requires specifying the set argument (e.g. set = "GT6")

iris |> 
  ggplot(aes(Sepal.Length, Petal.Length)) +
  geom_point(aes(colour = Petal.Length),
             size = rel(4), alpha = 1/1.2) +
  scale_nmr_color_sequential(pal = "GT6",
                             discrete = FALSE,
                             reverse = TRUE) +
  guides(color = "none")
#> Error in scale_nmr_color_sequential(pal = "GT6", discrete = FALSE, reverse = TRUE): Do not specify a 'pal'. This function implicitly uses pal = 'nondiverg'. Maybe you meant to specify a 'set'?