Discrete z-axis scale for 3D plots

scale_z_discrete creates a discrete scale for the z aesthetic in 3D plots. It works with categorical/factor data, positioning each level at integer coordinates (1, 2, 3, ...) in 3D space.

Usage

scale_z_discrete(
  name = waiver(),
  breaks = waiver(),
  labels = waiver(),
  limits = NULL,
  expand = waiver(),
  guide = "none",
  na.translate = TRUE,
  na.value = NA_real_,
  drop = TRUE,
  continuous.limits = NULL,
  ...
)

Arguments

name

The name of the scale, used as the axis title. Use waiver() for the default, or NULL to omit the title.

breaks

One of:

• NULL for no breaks

• waiver() for all breaks

• A character vector of breaks

• A function that takes the limits as input and returns breaks as output

labels

One of:

• NULL for no labels

• waiver() for the default labels

• A character vector giving labels (must be same length as breaks)

• A function that takes the breaks as input and returns labels as output

limits

A character vector that defines possible values of the scale and their order.

expand

A numeric vector of length two giving multiplicative and additive expansion constants. These constants ensure that data is placed some distance away from the axes. The defaults are to expand by 0.6 units on each side for discrete scales.

guide

A function used to create a guide or its name. Since z-axis guides are not yet supported, this defaults to "none".

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.

...

Other arguments passed on to discrete_scale().

Value

A ggplot2 scale object for the z aesthetic.

See also

scale_z_continuous for continuous z-axis scaling, coord_3d for the 3D coordinate system

Other 3D scale functions: scale_z_continuous(), zlim()

Examples

library(ggplot2)

# Basic usage to control order, breaks, labels, expansion, etc.
ggplot(mpg, aes(displ, cty, drv, color = drv)) +
      geom_point() +
      scale_z_discrete(limits = c("f", "r", "4"), # change default order
                       breaks = c("f", "r", "4"),
                       labels = c("front", "rear", "4-wheel"),
                       expand = expansion(.5)) +
      coord_3d()