Skip to contents

Plot a Cumulative Distribution Function

Source: R/geom_cdf.R
geom_cdf.Rd

geom_cdf() creates a ggplot2 layer that plots a cumulative distribution function (CDF) as a line. You can optionally shade a region by specifying a cumulative probability threshold via p, or a two-sided interval via p_lower and p_upper.

Usage

geom_cdf(
  mapping = NULL,
  data = NULL,
  stat = StatCDF,
  position = "identity",
  ...,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = FALSE,
  fun,
  xlim = NULL,
  n = 101,
  args = list(),
  fill = "grey20",
  color = "black",
  p = NULL,
  lower.tail = TRUE,
  p_lower = NULL,
  p_upper = NULL
)

StatCDF

GeomCDF

Format

An object of class StatCDF (inherits from Stat, ggproto, gg) of length 3.

An object of class GeomCDF (inherits from GeomArea, GeomRibbon, Geom, ggproto, gg) of length 2.

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

Ignored by stat_function(), do not use.

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 to 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 parameters passed on to ggplot2::layer().

na.rm

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. To include legend keys for all levels, even when no data exists, use TRUE. If NA, all levels are shown in legend, but unobserved levels are omitted.

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. annotation_borders().

fun

A function to compute the CDF (e.g. pnorm). The function must accept a numeric vector as its first argument and return values between 0 and 1.

xlim

A numeric vector of length 2 specifying the x-range over which to evaluate the CDF.

n

Number of points at which to evaluate fun.

args

A named list of additional arguments passed on to fun.

fill

Fill color for the shaded area.

color

Line color for the CDF curve.

p

(Optional) A numeric value between 0 and 1 specifying the threshold value of the CDF. The area will be shaded up until (if lower.tail = TRUE) or from (if lower.tail = FALSE) the point where the CDF reaches this value.

lower.tail

Logical; if TRUE (the default) shading is applied from the left end of the curve up to the threshold; if FALSE, shading is applied from the threshold to the right end.

p_lower

(Optional) A numeric value between 0 and 1 specifying the lower CDF threshold for two-sided shading. Used with p_upper.

p_upper

(Optional) A numeric value between 0 and 1 specifying the upper CDF threshold for two-sided shading. Used with p_lower.

Value

A ggplot2 layer.

Examples

  # Plot the standard normal CDF, shading up to the 97.5th percentile.
  ggplot() +
    geom_cdf(fun = pnorm, xlim = c(-3, 3), p = 0.975, lower.tail = TRUE)