R: Step ribbon plots.

geom_stepribbon {RcmdrPlugin.KMggplot2}

R Documentation

Step ribbon plots.

Description

geom_stepribbon is an extension of the geom_ribbon, and is optimized for Kaplan-Meier plots with pointwise confidence intervals or a confidence band.

Usage

geom_stepribbon(mapping = NULL, data = NULL, stat = "identity",
  position = "identity", na.rm = FALSE, show.legend = NA,
  inherit.aes = TRUE, kmplot = FALSE, ...)

Arguments

`mapping`	Set of aesthetic mappings created by `aes()` or `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, as a string.
`position`	Position adjustment, either as a string, or the result of a call to a position adjustment function.
`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.
`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()`.
`kmplot`	If `TRUE`, missing values are replaced by the previous values. This option is needed to make Kaplan-Meier plots if the last observation has event, in which case the upper and lower values of the last observation are missing. This processing is optimized for results from the survfit function.
`...`	Other arguments passed on to `layer()`. These are often aesthetics, used to set an aesthetic to a fixed value, like `colour = "red"` or `size = 3`. They may also be parameters to the paired geom/stat.

Aesthetics

@section Aesthetics: geom_ribbon()understands the following aesthetics (required aesthetics are in bold):

x
ymin
ymax
alpha
colour
fill
group
linetype
size

Learn more about setting these aesthetics in vignette("ggplot2-specs").

Examples

huron <- data.frame(year = 1875:1972, level = as.vector(LakeHuron))
h <- ggplot(huron, aes(year))
h + geom_stepribbon(aes(ymin = level - 1, ymax = level + 1), fill = "grey70") +
    geom_step(aes(y = level))
h + geom_ribbon(aes(ymin = level - 1, ymax = level + 1), fill = "grey70") +
    geom_line(aes(y = level))