The function xy stat applies a function to the x- and y-coordinates of a
layers positions by group. The stat_centroid()
and
stat_midpoint()
functions are convenience wrappers for calculating
centroids and midpoints. stat_funxy()
by default leaves the data
as-is, but can be supplied functions and arguments.
Usage
stat_funxy(
mapping = NULL,
data = NULL,
geom = "point",
position = "identity",
...,
funx = force,
funy = force,
argx = list(),
argy = list(),
crop_other = TRUE,
show.legend = NA,
inherit.aes = TRUE
)
stat_centroid(
...,
funx = mean,
funy = mean,
argx = list(na.rm = TRUE),
argy = list(na.rm = TRUE)
)
stat_midpoint(..., argx = list(na.rm = TRUE), argy = list(na.rm = 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)
).- geom
The geometric object to use to display the data, either as a
ggproto
Geom
subclass or as a string naming the geom stripped of thegeom_
prefix (e.g."point"
rather than"geom_point"
)- 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.- funx, funy
A
function
to call on the layer'sx
andy
positions respectively.- argx, argy
A named
list
containing arguments to thefunx
, andfuny
function calls.- crop_other
A
logical
of length one; whether the other data should be fitted to the length ofx
andy
(default:TRUE
). Useful to set toFALSE
whenfunx
orfuny
calculate summaries of length one that need to be recycled.- 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()
.
Details
This statistic only makes a minimal attempt at ensuring that the results from calling both functions are of equal length. Results of length 1 are recycled to match the longest length result.
Examples
p <- ggplot(iris, aes(Sepal.Width, Sepal.Length, colour = Species))
# Labelling group midpoints
p + geom_point() +
stat_midpoint(aes(label = Species, group = Species),
geom = "text", colour = "black")
# Drawing segments to centroids
p + geom_point() +
stat_centroid(aes(xend = Sepal.Width, yend = Sepal.Length),
geom = "segment", crop_other = FALSE)
# Drawing intervals
ggplot(iris, aes(Sepal.Width, Sepal.Length, colour = Species)) +
geom_point() +
stat_funxy(geom = "path",
funx = median, funy = quantile,
argy = list(probs = c(0.1, 0.9)))