scale_evanverse: Discrete Color and Fill Scales for evanverse Palettes

Description

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",
  ...
)

Value

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

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.

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

Examples

Run this code

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()