geom_contour {ggplot2} | R Documentation |
2D contours of a 3D surface
Description
ggplot2 can not draw true 3D surfaces, but you can use geom_contour()
,
geom_contour_filled()
, and geom_tile()
to visualise 3D surfaces in 2D.
These functions require regular data, where the x
and y
coordinates
form an equally spaced grid, and each combination of x
and y
appears
once. Missing values of z
are allowed, but contouring will only work for
grid points where all four corners are non-missing. If you have irregular
data, you'll need to first interpolate on to a grid before visualising,
using interp::interp()
, akima::bilinear()
, or similar.
Usage
geom_contour(
mapping = NULL,
data = NULL,
stat = "contour",
position = "identity",
...,
bins = NULL,
binwidth = NULL,
breaks = NULL,
lineend = "butt",
linejoin = "round",
linemitre = 10,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
geom_contour_filled(
mapping = NULL,
data = NULL,
stat = "contour_filled",
position = "identity",
...,
bins = NULL,
binwidth = NULL,
breaks = NULL,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
stat_contour(
mapping = NULL,
data = NULL,
geom = "contour",
position = "identity",
...,
bins = NULL,
binwidth = NULL,
breaks = NULL,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
stat_contour_filled(
mapping = NULL,
data = NULL,
geom = "contour_filled",
position = "identity",
...,
bins = NULL,
binwidth = NULL,
breaks = NULL,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)
Arguments
mapping |
Set of aesthetic mappings created by |
data |
The data to be displayed in this layer. There are three options: If A A |
stat |
The statistical transformation to use on the data for this layer.
When using a
|
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
|
... |
Other arguments passed on to
|
bins |
Number of contour bins. Overridden by |
binwidth |
The width of the contour bins. Overridden by |
breaks |
One of:
Overrides |
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 |
show.legend |
logical. Should this layer be included in the legends?
|
inherit.aes |
If |
geom |
The geometric object to use to display the data for this layer.
When using a
|
Aesthetics
geom_contour()
understands the following aesthetics (required aesthetics are in bold):
Learn more about setting these aesthetics in vignette("ggplot2-specs")
.
geom_contour_filled()
understands the following aesthetics (required aesthetics are in bold):
Learn more about setting these aesthetics in vignette("ggplot2-specs")
.
stat_contour()
understands the following aesthetics (required aesthetics are in bold):
Learn more about setting these aesthetics in vignette("ggplot2-specs")
.
stat_contour_filled()
understands the following aesthetics (required aesthetics are in bold):
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. The computed variables differ somewhat for contour lines (computed by stat_contour()
) and contour bands (filled contours, computed by stat_contour_filled()
). The variables nlevel
and piece
are available for both, whereas level_low
, level_high
, and level_mid
are only available for bands. The variable level
is a numeric or a factor depending on whether lines or bands are calculated.
-
after_stat(level)
Height of contour. For contour lines, this is a numeric vector that represents bin boundaries. For contour bands, this is an ordered factor that represents bin ranges. -
after_stat(level_low)
,after_stat(level_high)
,after_stat(level_mid)
(contour bands only) Lower and upper bin boundaries for each band, as well as the mid point between boundaries. -
after_stat(nlevel)
Height of contour, scaled to a maximum of 1. -
after_stat(piece)
Contour piece (an integer).
Dropped variables
z
After contouring, the z values of individual data points are no longer available.
See Also
geom_density_2d()
: 2d density contours
Examples
# Basic plot
v <- ggplot(faithfuld, aes(waiting, eruptions, z = density))
v + geom_contour()
# Or compute from raw data
ggplot(faithful, aes(waiting, eruptions)) +
geom_density_2d()
# use geom_contour_filled() for filled contours
v + geom_contour_filled()
# Setting bins creates evenly spaced contours in the range of the data
v + geom_contour(bins = 3)
v + geom_contour(bins = 5)
# Setting binwidth does the same thing, parameterised by the distance
# between contours
v + geom_contour(binwidth = 0.01)
v + geom_contour(binwidth = 0.001)
# Other parameters
v + geom_contour(aes(colour = after_stat(level)))
v + geom_contour(colour = "red")
v + geom_raster(aes(fill = density)) +
geom_contour(colour = "white")