You can use continuous positions even with a discrete position scale -
this allows you (e.g.) to place labels between bars in a bar chart.
Continuous positions are numeric values starting at one for the first
level, and increasing by one for each level (i.e. the labels are placed
at integer positions). This is what allows jittering to work.
scale_x_discrete(..., expand = waiver(), position = "bottom")
scale_y_discrete(..., expand = waiver(), position = "left")
Arguments passed on to
NULL for no breaks
waiver() for the default breaks computed by the
A character vector of breaks
A function that takes the limits as input and returns breaks
A character vector that defines possible values of the scale
and their order.
Should unused factor levels be omitted from the scale?
TRUE, uses the levels that appear in the data;
FALSE uses all the levels in the factor.
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.translate = TRUE, what value aesthetic
value should missing be displayed as? Does not apply to position scales
NA is always placed at the far right.
The names of the aesthetics that this scale works with
The name of the scale
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
The name of the scale. Used as 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
NULL for no labels
waiver() for the default labels computed by the
A character vector giving labels (must be same length as
A function that takes the breaks as input and returns labels
A function used to create a guide or its name. See
guides() for more info.
The super class to use for the constructed scale
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
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.
The position of the axis.
right for y
bottom for x axes
# The discrete position scale is added automatically whenever you
# have a discrete position.
(d <- ggplot
, carat > 1
d + scale_x_discrete("Cut")
d + scale_x_discrete("Cut", labels = c("Fair" = "F","Good" = "G",
"Very Good" = "VG","Perfect" = "P","Ideal" = "I"))
# Use limits to adjust the which levels (and in what order)
# are displayed
d + scale_x_discrete(limits = c("Fair","Ideal"))
#> Warning: Removed 11189 rows containing missing values (geom_point).
# you can also use the short hand functions xlim and ylim
#> Warning: Removed 9610 rows containing missing values (geom_point).
#> Warning: Removed 16770 rows containing missing values (geom_point).
# See ?reorder to reorder based on the values of another variable
)) + geom_point
# Use abbreviate as a formatter to reduce long names
(labels = abbreviate