The geom is an extension of geom_text() and geom_label() that allows you
to draw richly formatted text in marquee-markdown format in your plot. For
plain text it is a near-drop-in replacement for the above geoms except some
sizing might be very slightly different. However, using this geom you are
able to access the much more powerful font settings available in marquee, so
even then it might make sense to opt for this geom.
geom_marquee(
mapping = NULL,
data = NULL,
stat = "identity",
position = "identity",
...,
size.unit = "mm",
na.rm = FALSE,
show.legend = NA,
inherit.aes = TRUE
)A ggplot2 layer that can be added 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 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.
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.
How the size aesthetic is interpreted: as millimetres
("mm", default), points ("pt"), centimetres ("cm"), inches ("in"),
or picas ("pc").
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. 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.
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
Styling of the text is based on a style set with the exception that the
standard aesthetics such as family, size, colour, fill, etc. are recognized
and applied to the base tag style. The default style set (classic_style)
can be changed using the style aesthetic which can take a vector of style
sets so that each text can rely on it's own style if needed. As with
element_marquee(), the fill aesthetic is treated differently and not
applied to the base tag, but to the body tag as a skip_inherit() style so
as to not propagate the fill.
Contrary to the standard text and label geoms, geom_marquee() takes a
width aesthetic that can be used to turn on soft wrapping of text. The
default value (NA) lets the text run as long as it want's (honoring hard
breaks), but setting this to something else will instruct marquee to use at
most that amount of space. You can use grid units to set it to an absolute
amount. The default means that if the label contains no text at all (e.g. it
is only an image tag) then the width is zero and the content disappears. In
that case, you must provide a width.
library(ggplot2)
# Standard use
p <- ggplot(mtcars, aes(wt, mpg))
p + geom_marquee(aes(label = rownames(mtcars)))
# Make use of more powerful font features (note, result may depend on fonts
# installed on the system)
p + geom_marquee(
aes(label = rownames(mtcars)),
style = classic_style(weight = "thin", width = "condensed")
)
# Turn on line wrapping
p + geom_marquee(aes(label = rownames(mtcars)), width = unit(2, "cm"))
# Style like label
label_style <- modify_style(
classic_style(margin = trbl(0)),
"body",
padding = skip_inherit(trbl(4)),
border = "black",
border_size = skip_inherit(trbl(1)),
border_radius = 3
)
p + geom_marquee(aes(label = rownames(mtcars), fill = gear), style = label_style)
# Use markdown to style the text
red_bold_names <- sub("(\\w+)", "{.red **\\1**}", rownames(mtcars))
p + geom_marquee(aes(label = red_bold_names))
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