Contours from a 2d density estimate.
Source:R/geom-density2d.r
, R/stat-density-2d.r
geom_density_2d.Rd
Perform a 2D kernel density estimation using kde2d and display the results with contours. This can be useful for dealing with overplotting.
Usage
geom_density_2d(
mapping = NULL,
data = NULL,
stat = "density2d",
position = "identity",
...,
lineend = "butt",
linejoin = "round",
linemitre = 1,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
stat_density_2d(
mapping = NULL,
data = NULL,
geom = "density_2d",
position = "identity",
...,
contour = TRUE,
n = 100,
h = NULL,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
Arguments
- mapping
Set of aesthetic mappings created by
aes
oraes_
. 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.- position
Position adjustment, either as a string, or the result of a call to a position adjustment function.
- ...
other arguments passed on to
layer
. These are often aesthetics, used to set an aesthetic to a fixed value, likecolor = "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), removes missing values with a warning. IfTRUE
silently removes missing values.- 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.- 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_density_2d
andstat_density_2d
.- contour
If
TRUE
, contour the results of the 2d density estimation- n
number of grid points in each direction
- h
Bandwidth (vector of length two). If
NULL
, estimated usingbandwidth.nrd
.
Aesthetics
geom_density_2d
understands the following aesthetics (required aesthetics are in bold):
x
y
alpha
colour
linetype
size
Computed variables
Same as stat_contour
See also
geom_contour
for contour drawing geom,
stat_sum
for another way of dealing with overplotting
Examples
m <- ggplot(faithful, aes(x = eruptions, y = waiting)) +
geom_point() +
xlim(0.5, 6) +
ylim(40, 110)
m + geom_density_2d()
# \donttest{
m + stat_density_2d(aes(fill = ..level..), geom = "polygon")
#> Warning: NAs introduced by coercion
set.seed(4393)
dsmall <- diamonds[sample(nrow(diamonds), 1000), ]
d <- ggplot(dsmall, aes(x, y))
# If you map an aesthetic to a categorical variable, you will get a
# set of contours for each value of that variable
d + geom_density_2d(aes(colour = cut))
# If we turn contouring off, we can use use geoms like tiles:
d + stat_density_2d(geom = "raster", aes(fill = ..density..), contour = FALSE)
# Or points:
d + stat_density_2d(geom = "point", aes(size = ..density..), n = 20, contour = FALSE)
# }