The names of the aesthetics that this scale works with.
scale_name
The name of the scale
that should be used for error messages associated with this scale.
palette
A palette function that when called with a single integer
argument (the number of levels in the scale) returns the values that
they should take (e.g., scales::pal_hue()).
name
The name of the scale. Used as the axis or legend title. If
waiver(), the default, the name of the scale is taken from the first
mapping used for that aesthetic. If NULL, the legend title will be
omitted.
breaks
One of:
NULL for no breaks
waiver() for the default breaks (the scale limits)
A character vector of breaks
A function that takes the limits as input and returns breaks
as output. Also accepts rlang lambda function
notation.
labels
One of:
NULL for no labels
waiver() for the default labels computed by the
transformation object
A character vector giving labels (must be same length as breaks)
An expression vector (must be the same length as breaks). See ?plotmath for details.
A function that takes the breaks as input and returns labels
as output. Also accepts rlang lambda function
notation.
limits
One of:
NULL to use the default scale values
A character vector that defines possible values of the scale and their
order
A function that accepts the existing (automatic) values and returns
new ones. Also accepts rlang lambda function
notation.
na.translate
Unlike continuous scales, discrete scales can easily show
missing values, and do so by default. If you want to remove missing values
from a discrete scale, specify na.translate = FALSE.
na.value
If na.translate = TRUE, what aesthetic value should the
missing values be displayed as? Does not apply to position scales
where NA is always placed at the far right.
drop
Should unused factor levels be omitted from the scale?
The default, TRUE, uses the levels that appear in the data;
FALSE uses all the levels in the factor.
guide
A function used to create a guide or its name. See
guides() for more information.
call
The call used to construct the scale for reporting messages.