facet_nested_wrap: Ribbon of panels with nested strips.

Description

facet_nested_wrap() wraps a sequence of panels onto a two-dimensional layout, and nests grouped facets where possible.

Usage

facet_nested_wrap(
  facets,
  nrow = NULL,
  ncol = NULL,
  scales = "fixed",
  axes = "margins",
  remove_labels = "none",
  shrink = TRUE,
  labeller = "label_value",
  as.table = TRUE,
  drop = TRUE,
  dir = "h",
  strip.position = "top",
  nest_line = FALSE,
  resect = unit(0, "mm"),
  bleed = FALSE
)

Arguments

facets

A set of variables or expressions quoted by vars() and defining faceting groups on the rows or columns dimension. The variables can be named (the names are passed to labeller).

For compatibility with the classic interface, can also be a formula or character vector. Use either a one sided formula, ~a + b, or a character vector, c("a", "b").

nrow

Number of rows and columns.

ncol

Number of rows and columns.

scales

Should scales be fixed ("fixed", the default), free ("free"), or free in one dimension ("free_x", "free_y")?

axes

A character where axes should be drawn. Either "margins" (default), "rows", "cols" or "full". Only applies when the scale is free through the scales argument.

remove_labels

A character denoting what labels should be removed when axes are repeated and redundant. Either "none" (default), "rows", "cols" or "all". Only applies to relevant position guides included with the axes argument when scales are fixed.

shrink

If TRUE, will shrink scales to fit output of statistics, not raw data. If FALSE, will be range of raw data before statistical summary.

labeller

A function that takes one data frame of labels and returns a list or data frame of character vectors. Each input column corresponds to one factor. Thus there will be more than one with vars(cyl, am). Each output column gets displayed as one separate line in the strip label. This function should inherit from the "labeller" S3 class for compatibility with labeller(). You can use different labeling functions for different kind of labels, for example use label_parsed() for formatting facet labels. label_value() is used by default, check it for more details and pointers to other options.

as.table

If TRUE, the default, the facets are laid out like a table with highest values at the bottom-right. If FALSE, the facets are laid out like a plot with the highest value at the top-right.

drop

If TRUE, the default, all factor levels not used in the data will automatically be dropped. If FALSE, all factor levels will be shown, regardless of whether or not they appear in the data.

dir

Direction: either "h" for horizontal, the default, or "v", for vertical.

strip.position

By default, the labels are displayed on the top of the plot. Using strip.position it is possible to place the labels on either of the four sides by setting strip.position = c("top", "bottom", "left", "right")

nest_line

a logical vector of length 1, indicating whether to draw a nesting line to indicate the nesting of variables. Control the look of the nesting line by setting the ggh4x.facet.nestline theme element.

resect

a unit vector of length 1, indicating how much the nesting line should be shortened.

bleed

a logical vector of length 1, indicating whether merging of lower-level variables is allowed when the higher-level variables are separate. See details.

Value

A FacetNestedWrap ggproto object that can be added to a plot.

Details

This function inherits the capabilities of facet_wrap2().

This function only merges strips in the same row or column as they appear through regular facet_wrap() layout behaviour.

Hierarchies are inferred from the order of variables supplied to rows or cols. The first variable is interpreted to be the outermost variable, while the last variable is interpreted to be the innermost variable. They display order is always such that the outermost variable is placed the furthest away from the panels. Strips are automatically grouped when they span a nested variable.

The bleed argument controls whether lower-level variables are allowed to be merged when higher-level are different, i.e. they can bleed over hierarchies. Suppose the facet_wrap() behaviour would be the following:

[_1_][_2_][_2_] [_3_][_3_][_4_]

In such case, the default bleed = FALSE argument would result in the following:

[_1_][___2____] [_3_][_3_][_4_]

Whereas bleed = TRUE would allow the following:

[_1_][___2____] [___3____][_4_]

Examples

Run this code

# NOT RUN {
p <- ggplot(mpg, aes(displ, hwy)) +
  geom_point()
p + facet_nested_wrap(vars(cyl, drv))

# Controlling the nest line
p + facet_nested_wrap(vars(cyl, drv), nest_line = TRUE) +
  theme(ggh4x.facet.nestline = element_line(linetype = 3))

# Ignore nested hierarchies with the 'bleed' argument
 p + facet_nested_wrap(vars(drv, cyl), bleed = TRUE)
# }