geom_raster_filled

stat_levels() is the geom-agnostic engine of the level-binning family. It discretizes the continuous aesthetic z into a factor level via base::cut() and, by default, maps that level to fill so it can drive any geom (point, raster, tile, ...). stat_raster_levels() and stat_point_levels() are thin subclasses that reuse this binning logic and only change which aesthetic level is mapped to.

geom_raster_filled(
  mapping = NULL,
  data = NULL,
  stat = "raster_levels",
  position = "identity",
  ...,
  breaks = NULL,
  hjust = 0.5,
  vjust = 0.5,
  interpolate = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_raster_levels(
  mapping = NULL,
  data = NULL,
  geom = "raster",
  position = "identity",
  ...,
  breaks = NULL,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_levels(
  mapping = NULL,
  data = NULL,
  geom = "point",
  position = "identity",
  ...,
  breaks = NULL,
  include.lowest = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping

Set of aesthetic mappings created by 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. When using a geom_*() function to construct a layer, the stat argument can be used to override the default coupling between geoms and stats. The stat argument accepts the following:

A Stat ggproto subclass, for example StatCount.
A string naming the stat. To give the stat as a string, strip the function name of the stat_ prefix. For example, to use stat_count(), give the stat as "count".
For more information and other ways to specify the stat, see the layer stat documentation.

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 position argument accepts the following:

The result of calling a position function, such as position_jitter(). This method allows for passing extra arguments to the position.
A string naming the position adjustment. To give the position as a string, strip the function name of the position_ prefix. For example, to use position_jitter(), give the position as "jitter".
For more information and other ways to specify the position, see the layer position documentation.

...

Other arguments passed on to layer()'s params argument. These arguments broadly fall into one of 4 categories below. Notably, further arguments to the position argument, or aesthetics that are required can not be passed through .... Unknown arguments that are not part of the 4 categories below are ignored.

Static aesthetics that are not mapped to a scale, but are at a fixed value and apply to the layer as a whole. For example, colour = "red" or linewidth = 3. The geom's documentation has an Aesthetics section that lists the available options. The 'required' aesthetics cannot be passed on to the params. Please note that while passing unmapped aesthetics as vectors is technically possible, the order and required length is not guaranteed to be parallel to the input data.
When constructing a layer using a stat_*() function, the ... argument can be used to pass on parameters to the geom part of the layer. An example of this is stat_density(geom = "area", outline.type = "both"). The geom's documentation lists which parameters it can accept.
Inversely, when constructing a layer using a geom_*() function, the ... argument can be used to pass on parameters to the stat part of the layer. An example of this is geom_area(stat = "density", adjust = 0.5). The stat's documentation lists which parameters it can accept.
The key_glyph argument of layer() may also be passed on through .... This can be one of the functions described as key glyphs, to change the display of the layer in the legend.

breaks

Numeric vector of break points passed to base::cut() to bin z into discrete levels. When NULL (the default), pretty(z, 7) is used. To capture values below the smallest / above the largest break, include -Inf / Inf in breaks (e.g. c(-Inf, 2, 4, 6, Inf)); otherwise out-of-range values become NA and are dropped. This is the opposite of the continuous scale_*_stepsn() path, which requires finite breaks.

hjust, vjust

horizontal and vertical justification of the grob. Each justification value should be a number between 0 and 1. Defaults to 0.5 for both, centering each pixel over its data location.

interpolate

If TRUE interpolate linearly, if FALSE (the default) don't interpolate.

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. To include legend keys for all levels, even when no data exists, use TRUE. If NA, all levels are shown in legend, but unobserved levels are omitted.

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. annotation_borders().

geom

The geometric object to use to display the data for this layer. When using a stat_*() function to construct a layer, the geom argument can be used to override the default coupling between stats and geoms. The geom argument accepts the following:

A Geom ggproto subclass, for example GeomPoint.
A string naming the geom. To give the geom as a string, strip the function name of the geom_ prefix. For example, to use geom_point(), give the geom as "point".
For more information and other ways to specify the geom, see the layer geom documentation.

include.lowest

Logical, passed to base::cut(). If TRUE, a value equal to the lowest break is included in the first interval. This only rescues the boundary value itself; it does not capture values truly below the lowest break (use -Inf for that).

Computed variables

level: the factor produced by cut(z, breaks); map it to an aesthetic with after_stat(level).

Aesthetics

stat_levels() requires the z aesthetic and, by default, maps the computed level to fill. To colour points instead, either map it explicitly with aes(colour = after_stat(level)) and silence the unused default fill legend via guides(fill = "none"), or use the dedicated geom_point_levels() / stat_point_levels(), which map only colour.

Examples

library(rcolors)
library(ggplot2)
library(magrittr)

df = data.frame(x = 1:10, y = 1:10, z = 1:10)

brks <- c(2, 4, 6, 8) %>% c(-Inf, ., Inf) # 这里要包含
nbrk <- length(brks) - 1
cols = get_color(rcolors$amwg256, nbrk)

ggplot(df, aes(x, y, z = x)) +
  stat_levels(aes(color = after_stat(level)), breaks = brks, geom = "point") +
  scale_color_manual(
    values = cols,
    guide = guide_coloursteps2(title = "lgd", barheight = unit(0.8, "npc"))
  ) +
  guides(fill = "none")


## another option: use `scale_color_stepsn`
# example 2
# NOTE: `scale_*_stepsn` is a *continuous* binned scale, so `breaks` must be
# finite. Passing -Inf/Inf makes the open-ended end bins rescale to a
# non-finite value -> palette returns NA -> drawn as grey (na.value). Drop the
# infinite breaks here; the open-ended triangles are still drawn by
# `guide_coloursteps2()` (which always renders triangle ends), so no semantics
# are lost. Note the bin colours are *interpolated* along the gradient and thus
# only approximate `cols`; for exact per-level colours use the discrete `cut`
# path above (stat_levels + scale_color_manual).
ggplot(df, aes(x, y, color = x)) +
  geom_point() +
  scale_color_stepsn(
    colors = cols,
    breaks = brks[is.finite(brks)],
    guide = guide_coloursteps2(title = "lgd")
  ) +
  theme(
    legend.title = element_blank(),
    legend.margin = margin(l = -2)
  )


# example 3 
df <- expand.grid(X1 = 1:10, X2 = 1:10)
df$value <- df$X1 * df$X2

brks = c(10, 15, 25, 50)
nbrk <- length(brks) + 1
cols = get_color(rcolors$amwg256, nbrk)

# This can be changed with the `even.steps` argument
ggplot(df, aes(X1, X2)) +
  geom_tile(aes(fill = value)) +
  scale_fill_stepsn(
    colors = cols, breaks = brks,
    guide = guide_colorsteps2()
  ) +
  theme(
    legend.title = element_blank(),
    legend.margin = margin(l = -2)
  )

Arguments

Computed variables

Aesthetics

See also

Examples