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::hue_pal()
).
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.
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.
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.
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
.
scale_name
The name of the scale that should be used for error messages
associated with this scale.
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.
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.
guide
A function used to create a guide or its name. See
guides()
for more information.
expand
For position scales, a vector of range expansion constants used to add some
padding around the data to ensure that they are placed some distance
away from the axes. Use the convenience function expansion()
to generate the values for the expand
argument. The defaults are to
expand the scale by 5% on each side for continuous variables, and by
0.6 units on each side for discrete variables.
position
For position scales, The position of the axis.
left
or right
for y axes, top
or bottom
for x axes.
super
The super class to use for the constructed scale