What is scale_fill_distiller() Function in R

The scale_fill_distiller() is a function from the ggplot2 package in the R that applies a color scale to the fill aesthetic of a plot. For example, scale_fill_distiller(palette = “Spectral”, n = 7) will create a color scale with 7 colors from the Spectral palette.

Syntax

scale_fill_distiller(
  ...,
  type = "seq",
  palette = 1,
  direction = -1,
  values = NULL,
  space = "Lab",
  na.value = "grey50",
  guide = "colourbar",
  aesthetics = "fill"
)

Parameters

type: It is one of “seq” (sequential), “div” (diverging), or “qual” (qualitative)

palette: If a string will use that named palette. If a number will index into the list of palettes of the appropriate type. The list of available palettes can be found in the Palettes section.

direction: It sets the order of colors in the scale. If 1, the default colors are as output by RColorBrewer::brewer.pal(). If -1, the order of colors is reversed.

aesthetics: The character string or vector of character strings listing the name(s) of the aesthetic(s) that this scale works with.

guide: Type of legend. Use “colourbar” for continuous color bar or “legend” for discrete color legend.

na.value: It is a color for missing values.

values: If colours are not evenly positioned along the gradient, this vector gives the position (between 0 and 1) for each colour in the colours vector.

space: It is a colour space in which to calculate the gradient. Must be “Lab” – other values are deprecated.

: Other arguments.

Example

library(ggplot2)

# Create a scatterplot of car data
ggplot(mpg, aes(x = displ, y = hwy, color = class)) +
  geom_point(size = 3) +
  labs(
    title = "Fuel Efficiency by Engine Displacement and Vehicle Class",
    x = "Engine Displacement (L)", y = "Highway Fuel Economy (mpg)",
    color = "Vehicle Class"
  ) +
  scale_fill_distiller(palette = "Spectral", direction = 1,
                       name = "Vehicle Class")

Output

scale_fill_distiller() Function in R

In this example, the scale_fill_distiller() function applies a distiller color scheme to the fill aesthetic of the plot based on the class variable.

The palette argument specifies the name of the color scheme to use (“Spectral”), the direction argument specifies the direction of the color gradient (1 for increasing values), and the name argument specifies the name of the legend for the color scale.

That’s it.

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