scale_x_discrete

Discrete position.

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.

Usage

scale_x_discrete(..., expand = waiver())
  scale_y_discrete(..., expand = waiver())

See Also

Other position scales: scale_x_continuous, scale_x_date, scale_x_datetime, scale_x_log10, scale_x_reverse, scale_x_sqrt, scale_y_continuous, scale_y_date, scale_y_datetime, scale_y_log10, scale_y_reverse, scale_y_sqrt

Aliases

• scale_x_discrete
• scale_y_discrete

Examples

qplot(cut, data=diamonds, stat="bin")
qplot(cut, data=diamonds, geom="bar")

# The discrete position scale is added automatically whenever you
# have a discrete position.

(d <- qplot(cut, clarity, data=subset(diamonds, carat > 1), geom="jitter"))

d + scale_x_discrete("Cut")
d + scale_x_discrete("Cut", labels = c("Fair" = "F","Good" = "G",
  "Very Good" = "VG","Perfect" = "P","Ideal" = "I"))

d + scale_y_discrete("Clarity")
d + scale_x_discrete("Cut") + scale_y_discrete("Clarity")

# Use limits to adjust the which levels (and in what order)
# are displayed
d + scale_x_discrete(limits=c("Fair","Ideal"))

# you can also use the short hand functions xlim and ylim
d + xlim("Fair","Ideal", "Good")
d + ylim("I1", "IF")

# See ?reorder to reorder based on the values of another variable
qplot(manufacturer, cty, data=mpg)
qplot(reorder(manufacturer, cty), cty, data=mpg)
qplot(reorder(manufacturer, displ), cty, data=mpg)

# Use abbreviate as a formatter to reduce long names
qplot(reorder(manufacturer, cty), cty, data=mpg) +
  scale_x_discrete(labels = abbreviate)