gf_count: Formula interface to geom_count()

In ggformula: Formula Interface to the Grammar of Graphics

Formula interface to geom_count()

Description

This is a variant geom_point() that counts the number of observations at each location, then maps the count to point area. It useful when you have discrete data and overplotting.

Usage

gf_count(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  alpha,
  color,
  fill,
  group,
  shape,
  size,
  stroke,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  geom = "point",
  stat = "sum",
  position = "identity",
  show.legend = NA,
  show.help = NULL,
  inherit = TRUE,
  environment = parent.frame()
)

Arguments

object	When chaining, this holds an object produced in the earlier portions of the chain. Most users can safely ignore this argument. See details and examples.
gformula	A formula with shape y ~ x. Faceting can be achieved by including | in the formula.
data	A data frame with the variables to be plotted.
...	Additional arguments. Typically these are (a) ggplot2 aesthetics to be set with attribute = value, (b) ggplot2 aesthetics to be mapped with attribute = ~ expression, or (c) attributes of the layer as a whole, which are set with attribute = value.
alpha	Opacity (0 = invisible, 1 = opaque).
color	A color or a formula used for mapping color.
fill	A color for filling, or a formula used for mapping fill.
group	Used for grouping.
shape	An integer or letter shape or a formula used for mapping shape.
size	A numeric size or a formula used for mapping size.
stroke	A numeric size of the border or a formula used to map stroke.
xlab	Label for x-axis. See also gf_labs().
ylab	Label for y-axis. See also gf_labs().
title, subtitle, caption	Title, sub-title, and caption for the plot. See also gf_labs().
geom	A character string naming the geom used to make the layer.
stat	A character string naming the stat used to make the layer.
position	Either a character string naming the position function used for the layer or a position object returned from a call to a position function.
show.legend	A logical indicating whether this layer should be included in the legends. NA, the default, includes layer in the legends if any of the attributes of the layer are mapped.
show.help	If TRUE, display some minimal help.
inherit	A logical indicating whether default attributes are inherited.
environment	An environment in which to look for variables not found in data.

Value

a gg object

Specifying plot attributes

Positional attributes (a.k.a, aesthetics) are specified using the formula in gformula. Setting and mapping of additional attributes can be done through the use of additional arguments. Attributes can be set can be set using arguments of the form attribute = value or mapped using arguments of the form attribute = ~ expression.

In formulas of the form A | B, B will be used to form facets using facet_wrap() or facet_grid(). This provides an alternative to gf_facet_wrap() and gf_facet_grid() that is terser and may feel more familiar to users of lattice.

Evaluation

Evaluation of the ggplot2 code occurs in the environment of gformula. This will typically do the right thing when formulas are created on the fly, but might not be the right thing if formulas created in one environment are used to create plots in another.

See Also

ggplot2::geom_count()

Examples

# Best used in conjunction with scale_size_area which ensures that
# counts of zero would be given size 0. This doesn't make much difference
# here because the smallest count is already close to 0.

gf_count(hwy ~ cty, data = mpg, alpha = 0.3) |>
  gf_refine(scale_size_area())

ggformula documentation built on Nov. 9, 2023, 5:08 p.m.