This geom lets you annotate sets of points via polygonal shapes.
Unlike other ggforce::geom_mark_* functions, geom_mark_shape should be explicitly
provided with the shape coordinates. As in ggforce::geom_shape, the polygon can be
expanded/contracted and corners can be rounded, which is controlled by expand and
radius parameters.
geom_mark_shape(
mapping = NULL,
data = NULL,
stat = "identity",
position = "identity",
expand = 0,
radius = 0,
label.margin = margin(2, 2, 2, 2, "mm"),
label.width = NULL,
label.minwidth = unit(50, "mm"),
label.hjust = 0,
label.fontsize = 12,
label.family = "",
label.lineheight = 1,
label.fontface = c("bold", "plain"),
label.fill = "white",
label.colour = "black",
label.buffer = unit(10, "mm"),
con.colour = "black",
con.size = 0.5,
con.type = "elbow",
con.linetype = 1,
con.border = "one",
con.cap = unit(3, "mm"),
con.arrow = NULL,
...,
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)A ggplot2 layer (ggplot2::layer) that adds polygonal shape annotations to a plot.
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.
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)).
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 the 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.
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.
A numeric or unit vector of length one, specifying the expansion amount. Negative values will result in contraction instead. If the value is given as a numeric it will be understood as a proportion of the plot area width.
As expand but specifying the corner radius.
The margin around the annotation boxes, given by a call
to ggplot2::margin().
A fixed width for the label. Set to NULL to let the text
or label.minwidth decide.
The minimum width to provide for the description. If the size of the label exceeds this, the description is allowed to fill as much as the label.
The horizontal justification for the annotation. If it contains two elements the first will be used for the label and the second for the description.
The size of the text for the annotation. If it contains two elements the first will be used for the label and the second for the description.
The font family used for the annotation. If it contains two elements the first will be used for the label and the second for the description.
The height of a line as a multipler of the fontsize. If it contains two elements the first will be used for the label and the second for the description.
The font face used for the annotation. If it contains two elements the first will be used for the label and the second for the description.
The fill colour for the annotation box. Use "inherit" to
use the fill from the enclosure or "inherit_col" to use the border colour
of the enclosure.
The text colour for the annotation. If it contains
two elements the first will be used for the label and the second for the
description. Use "inherit" to use the border colour of the enclosure or
"inherit_fill" to use the fill colour from the enclosure.
The size of the region around the mark where labels cannot be placed.
The colour for the line connecting the annotation to the
mark. Use "inherit" to use the border colour of the enclosure or
"inherit_fill" to use the fill colour from the enclosure.
The width of the connector. Use "inherit" to use the border
width of the enclosure.
The type of the connector. Either "elbow", "straight", or
"none".
The linetype of the connector. Use "inherit" to use the
border linetype of the enclosure.
The bordertype of the connector. Either "one" (to draw a
line on the horizontal side closest to the mark), "all" (to draw a border
on all sides), or "none" (not going to explain that one).
The distance before the mark that the line should stop at.
An arrow specification for the connection using
grid::arrow() for the end pointing towards the mark.
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.
If FALSE, the default, missing values are removed with
a warning. If TRUE, missing values are silently removed.
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.
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_mark_shape understand the following aesthetics (required aesthetics are
in bold):
x
y
x0 (used to anchor the label)
y0 (used to anchor the label)
filter
label
description
color
fill
group
size
linetype
alpha
All geom_mark_* allow you to put descriptive textboxes connected to the
mark on the plot, using the label and description aesthetics. The
textboxes are automatically placed close to the mark, but without obscuring
any of the datapoints in the layer. The placement is dynamic so if you resize
the plot you'll see that the annotation might move around as areas become big
enough or too small to fit the annotation. If there's not enough space for
the annotation without overlapping data it will not get drawn. In these cases
try resizing the plot, change the size of the annotation, or decrease the
buffer region around the marks.
Often marks are used to draw attention to, or annotate specific features of
the plot and it is thus not desirable to have marks around everything. While
it is possible to simply pre-filter the data used for the mark layer, the
geom_mark_* geoms also comes with a dedicated filter aesthetic that, if
set, will remove all rows where it evalutates to FALSE. There are
multiple benefits of using this instead of prefiltering. First, you don't
have to change your data source, making your code more adaptable for
exploration. Second, the data removed by the filter aesthetic is remembered
by the geom, and any annotation will take care not to overlap with the
removed data.
library(ggplot2)
shape1 <- data.frame(
x = c(0, 3, 3, 2, 2, 1, 1, 0),
y = c(0, 0, 3, 3, 1, 1, 3, 3),
label="bracket"
)
shape2 <- data.frame(
x = c(0, 3, 3, 0)+4,
y = c(0, 0, 3, 3),
label="square"
)
shape3 <- data.frame(
x = c(0, 1.5, 3, 1.5)+8,
y = c(1.5, 0, 1.5, 3),
label="diamond"
)
ggplot(rbind(shape1, shape2, shape3), aes(x=x, y=y, label=label, color=label, fill=label)) +
geom_mark_shape() +
ylim(0, 5)
Run the code above in your browser using DataLab