Line + multiple-ribbon plots (ggplot geom)

A combination of geom_line() and geom_ribbon() with default aesthetics designed for use with output from point_interval().

geom_lineribbon(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  step = FALSE,
  orientation = NA,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  check.aes = TRUE,
  check.param = TRUE
)

Arguments

mapping

Set of aesthetic mappings created by aes(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.

data

The data to be displayed in this layer. There are three options:

If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot().

A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created.

A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data. A function can be created from a formula (e.g. ~ head(.x, 10)).

stat

The statistical transformation to use on the data for this layer. When using a geom_*() function to construct a layer, the stat argument can be used the override the default coupling between geoms and stats. The stat argument accepts the following:

A Stat ggproto subclass, for example StatCount.
A string naming the stat. To give the stat as a string, strip the function name of the stat_ prefix. For example, to use stat_count(), give the stat as "count".
For more information and other ways to specify the stat, see the layer stat documentation.

position

A position adjustment to use on the data for this layer. This can be used in various ways, including to prevent overplotting and improving the display. The position argument accepts the following:

The result of calling a position function, such as position_jitter(). This method allows for passing extra arguments to the position.
A string naming the position adjustment. To give the position as a string, strip the function name of the position_ prefix. For example, to use position_jitter(), give the position as "jitter".
For more information and other ways to specify the position, see the layer position documentation.

...

Other arguments passed to layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like colour = "red" or linewidth = 3 (see Aesthetics, below). They may also be parameters to the paired geom/stat.

step

<scalar logical | string> Should the line/ribbon be drawn as a step function? One of:

FALSE (default): do not draw as a step function.
"mid" (or TRUE): draw steps midway between adjacent x values.
"hv": draw horizontal-then-vertical steps.
"vh": draw as vertical-then-horizontal steps.

TRUE is an alias for "mid", because for a step function with ribbons "mid" is reasonable default (for the other two step approaches the ribbons at either the very first or very last x value will not be visible).

orientation

<string> Whether this geom is drawn horizontally or vertically. One of:

NA (default): automatically detect the orientation based on how the aesthetics are assigned. Automatic detection works most of the time.
"horizontal" (or "y"): draw horizontally, using the y aesthetic to identify different groups. For each group, uses the x, xmin, xmax, and thickness aesthetics to draw points, intervals, and slabs.
"vertical" (or "x"): draw vertically, using the x aesthetic to identify different groups. For each group, uses the y, ymin, ymax, and thickness aesthetics to draw points, intervals, and slabs.

For compatibility with the base ggplot naming scheme for orientation, "x" can be used as an alias for "vertical" and "y" as an alias for "horizontal" (ggdist had an orientation parameter before base ggplot did, hence the discrepancy).

na.rm

<scalar logical> If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.

show.legend

logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display.

inherit.aes

If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().

check.aes, check.param

If TRUE, the default, will check that supplied parameters and aesthetics are understood by the geom or stat. Use FALSE to suppress the checks.

Value

A ggplot2::Geom representing a combined line + multiple-ribbon geometry which can be added to a ggplot() object.

Details

geom_lineribbon() is a combination of a geom_line() and geom_ribbon() designed for use with output from point_interval(). This geom sets some default aesthetics equal to the .width column generated by the point_interval() family of functions, making them often more convenient than a vanilla geom_ribbon() + geom_line().

Specifically, geom_lineribbon() acts as if its default aesthetics are aes(fill = forcats::fct_rev(ordered(.width))).

Aesthetics

The line+ribbon stats and geoms have a wide variety of aesthetics that control the appearance of their two sub-geometries: the line and the ribbon.

Positional aesthetics

x: x position of the geometry
y: y position of the geometry

Ribbon-specific aesthetics

xmin: Left edge of the ribbon sub-geometry (if orientation = "horizontal").
xmax: Right edge of the ribbon sub-geometry (if orientation = "horizontal").
ymin: Lower edge of the ribbon sub-geometry (if orientation = "vertical").
ymax: Upper edge of the ribbon sub-geometry (if orientation = "vertical").
order: The order in which ribbons are drawn. Ribbons with the smallest mean value of order are drawn first (i.e., will be drawn below ribbons with larger mean values of order). If order is not supplied to geom_lineribbon(), -abs(xmax - xmin) or -abs(ymax - ymax) (depending on orientation) is used, having the effect of drawing the widest (on average) ribbons on the bottom. stat_lineribbon() uses order = after_stat(level) by default, causing the ribbons generated from the largest .width to be drawn on the bottom.

Color aesthetics

colour: (or color) The color of the line sub-geometry.
fill: The fill color of the ribbon sub-geometry.
alpha: The opacity of the line and ribbon sub-geometries.
fill_ramp: A secondary scale that modifies the fill scale to "ramp" to another color. See scale_fill_ramp() for examples.

Line aesthetics

linewidth: Width of line. In ggplot2 < 3.4, was called size.
linetype: Type of line (e.g., "solid", "dashed", etc)

Other aesthetics (these work as in standard geoms)

group

See examples of some of these aesthetics in action in vignette("lineribbon"). Learn more about the sub-geom override aesthetics (like interval_color) in the scales documentation. Learn more about basic ggplot aesthetics in vignette("ggplot2-specs").

Author

Matthew Kay

Examples


library(dplyr)
library(ggplot2)

theme_set(theme_ggdist())

set.seed(12345)
tibble(
  x = rep(1:10, 100),
  y = rnorm(1000, x)
) %>%
  group_by(x) %>%
  median_qi(.width = c(.5, .8, .95)) %>%
  ggplot(aes(x = x, y = y, ymin = .lower, ymax = .upper)) +
  # automatically uses aes(fill = forcats::fct_rev(ordered(.width)))
  geom_lineribbon() +
  scale_fill_brewer()