Chromatic guide

This 'guide' is not really a guide, but a decision function for chromatic scales. It chooses the guide based on the number of channels a chromatic scale has seen data from. It is the default guide for the chromatic scales.

guide_chromatic(
  title = waiver(),
  ...,
  available_aes = c("colour", "color", "fill")
)

Arguments

title	A character string or expression indicating a title of guide. If NULL, the title is not shown. By default (waiver()), the name of the scale object or the name specified in labs() is used for the title.
...	Captures arguments to pass down to the constructor of the chosen guide.
available_aes	A vector of character strings listing the aesthetics for which a colourbar can be drawn.

Value

A chromatic_guide S3 object.

Details

This 'guide' chooses in the following ways based on the number of channels for which data is available.

0 channels

chooses guide_none()

1 channel

chooses guide_colourbar2()

2 channels

chooses guide_colourrect()

3 channels

chooses guide_colourcube()

More channels

chooses guide_colourcube() with 3 channels

See also

The scale_chromatic page for chromatic scales.

Other guides for chromatic scales: guide_colourbar2(), guide_colourcube(), guide_colourrect()

Examples

# Setup example plot
df <- data.frame(
  x = c(row(volcano)), y = c(col(volcano)), z = c(volcano)
)
g <- ggplot(df, aes(x, y)) +
  guides(fill = guide_chromatic())

# When the colour space has 3 defined channels, it makes a cube
g + geom_raster(aes(fill = cmy_spec(x, y, z)))

# When 2 channels are defined, it makes a rectangle
g + geom_raster(aes(fill = cmy_spec(x, z)))

# One defined channel gives a colour bar
g + geom_raster(aes(fill = cmy_spec(z)))