This fits a quantile regression to the data and draws the fitted quantiles
with lines. This is as a continuous analogue to geom_boxplot()
.
Usage
geom_quantile(
mapping = NULL,
data = NULL,
stat = "quantile",
position = "identity",
...,
lineend = "butt",
linejoin = "round",
linemitre = 10,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
stat_quantile(
mapping = NULL,
data = NULL,
geom = "quantile",
position = "identity",
...,
quantiles = c(0.25, 0.5, 0.75),
formula = NULL,
method = "rq",
method.args = list(),
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
Arguments
- mapping
Set of aesthetic mappings created by
aes()
. If specified andinherit.aes = TRUE
(the default), it is combined with the default mapping at the top level of the plot. You must supplymapping
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 toggplot()
.A
data.frame
, or other object, will override the plot data. All objects will be fortified to produce a data frame. Seefortify()
for which variables will be created.A
function
will be called with a single argument, the plot data. The return value must be adata.frame
, and will be used as the layer data. Afunction
can be created from aformula
(e.g.~ head(.x, 10)
).- position
Position adjustment, either as a string naming the adjustment (e.g.
"jitter"
to useposition_jitter
), or the result of a call to a position adjustment function. Use the latter if you need to change the settings of the adjustment.- ...
Other arguments passed on to
layer()
. These are often aesthetics, used to set an aesthetic to a fixed value, likecolour = "red"
orsize = 3
. They may also be parameters to the paired geom/stat.- lineend
Line end style (round, butt, square).
- linejoin
Line join style (round, mitre, bevel).
- linemitre
Line mitre limit (number greater than 1).
- na.rm
If
FALSE
, the default, missing values are removed with a warning. IfTRUE
, 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, andTRUE
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()
.- geom, stat
Use to override the default connection between
geom_quantile()
andstat_quantile()
.- quantiles
conditional quantiles of y to calculate and display
- formula
formula relating y variables to x variables
- method
Quantile regression method to use. Available options are
"rq"
(forquantreg::rq()
) and"rqss"
(forquantreg::rqss()
).- method.args
List of additional arguments passed on to the modelling function defined by
method
.
Aesthetics
geom_quantile()
understands the following aesthetics (required aesthetics are in bold):
x
y
alpha
colour
group
linetype
linewidth
weight
Learn more about setting these aesthetics in vignette("ggplot2-specs")
.
Computed variables
These are calculated by the 'stat' part of layers and can be accessed with delayed evaluation.
after_stat(quantile)
Quantile of distribution.
Examples
m <-
ggplot(mpg, aes(displ, 1 / hwy)) +
geom_point()
m + geom_quantile()
#> Smoothing formula not specified. Using: y ~ x
m + geom_quantile(quantiles = 0.5)
#> Smoothing formula not specified. Using: y ~ x
q10 <- seq(0.05, 0.95, by = 0.05)
m + geom_quantile(quantiles = q10)
#> Smoothing formula not specified. Using: y ~ x
# You can also use rqss to fit smooth quantiles
m + geom_quantile(method = "rqss")
#> Smoothing formula not specified. Using: y ~ qss(x, lambda = 1)
# Note that rqss doesn't pick a smoothing constant automatically, so
# you'll need to tweak lambda yourself
m + geom_quantile(method = "rqss", lambda = 0.1)
#> Smoothing formula not specified. Using: y ~ qss(x, lambda = 0.1)
# Set aesthetics to fixed value
m + geom_quantile(colour = "red", linewidth = 2, alpha = 0.5)
#> Smoothing formula not specified. Using: y ~ x