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Discrete Color and Fill Scales for evanverse Palettes

Source: R/scale_evanverse_discrete.R
scale_evanverse.Rd

Apply evanverse color palettes to ggplot2 discrete scales. These functions provide a seamless integration between evanverse palettes and ggplot2's color/fill aesthetics.

Usage

scale_color_evanverse(
  palette,
  type = NULL,
  n = NULL,
  reverse = FALSE,
  na.value = "grey50",
  guide = "legend",
  ...
)

scale_fill_evanverse(
  palette,
  type = NULL,
  n = NULL,
  reverse = FALSE,
  na.value = "grey50",
  guide = "legend",
  ...
)

scale_colour_evanverse(
  palette,
  type = NULL,
  n = NULL,
  reverse = FALSE,
  na.value = "grey50",
  guide = "legend",
  ...
)

Arguments

palette

Character. Name of the palette (e.g., "qual_vivid", "seq_blues"). Type will be automatically inferred from the prefix if not specified.

type

Character. Palette type: "sequential", "diverging", or "qualitative". If NULL (default), the type is automatically inferred from the palette name prefix.

n

Integer. Number of colors to use. If NULL (default), all colors from the palette are used. If n exceeds the number of colors in the palette, an error will be raised.

reverse

Logical. Should the color order be reversed? Default is FALSE.

na.value

Character. Color to use for NA values. Default is "grey50".

guide

Character or function. Type of legend. Use "legend" for standard legend or "none" to hide the legend. See guide_legend for more options.

...

Additional arguments passed to scale_color_manual or scale_fill_manual, such as name, labels, limits, etc.

Value

A ggplot2 scale object that can be added to a ggplot.

Details

The scale_color_evanverse() and scale_fill_evanverse() functions automatically:

  • Infer palette type from the naming convention (seq_, div_, qual_)

  • Handle color interpolation intelligently based on palette type:

    • Qualitative palettes: Direct color selection (no interpolation)

    • Sequential/Diverging palettes: Smooth interpolation when n < palette size

  • Support all standard ggplot2 scale parameters

  • Provide informative error messages and warnings

See also

get_palette for retrieving palette colors, list_palettes for available palettes, scale_color_manual for the underlying ggplot2 function.

Examples

library(ggplot2)

# Basic usage with automatic type inference
ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3, alpha = 0.8) +
  scale_color_evanverse("qual_vivid") +
  theme_minimal()


# Fill scale for boxplots
ggplot(iris, aes(x = Species, y = Sepal.Length, fill = Species)) +
  geom_boxplot(alpha = 0.7) +
  scale_fill_evanverse("qual_vivid") +
  theme_minimal()


# Reverse color order
ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3) +
  scale_color_evanverse("qual_vivid", reverse = TRUE) +
  theme_minimal()


# Explicitly specify type
ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3) +
  scale_color_evanverse("qual_vivid", type = "qualitative") +
  theme_minimal()


# Limit number of colors
ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3) +
  scale_color_evanverse("qual_vivid", n = 3) +
  theme_minimal()


# Custom legend name and labels
ggplot(iris, aes(Sepal.Length, Sepal.Width, color = Species)) +
  geom_point(size = 3) +
  scale_color_evanverse(
    "qual_vivid",
    name = "Iris Species",
    labels = c("Setosa", "Versicolor", "Virginica")
  ) +
  theme_minimal()


# Bar plot with fill
ggplot(mtcars, aes(x = factor(cyl), fill = factor(cyl))) +
  geom_bar() +
  scale_fill_evanverse("qual_vibrant") +
  labs(x = "Cylinders", y = "Count", fill = "Cylinders") +
  theme_minimal()