gf_polygon: Formula interface to geom_polygon()

In ggformula: Formula Interface to the Grammar of Graphics

Formula interface to geom_polygon()

Description

Line plots in ggformula. gf_path() differs from gf_line() in that points are connected in the order in which they appear in data.

Usage

gf_polygon(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  alpha,
  color,
  linewidth,
  shape,
  fill,
  group,
  stroke,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  geom = "polygon",
  stat = "identity",
  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.
linewidth	A numerical line width or a formula used for mapping linewidth.
shape, stroke	Aesthetics for polygons.
fill	A color for filling, or a formula used for mapping fill.
group	Used for grouping.
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_line(), gf_point()

Examples

gf_polygon()
if (require(maps) && require(ggthemes) && require(dplyr)) {
  US <- map_data("state") |>
    dplyr::mutate(name_length = nchar(region))
  States <- US |>
    dplyr::group_by(region) |>
    dplyr::summarise(lat = mean(range(lat)), long = mean(range(long))) |>
    dplyr::mutate(name = abbreviate(region, 3))

  gf_polygon(lat ~ long,
    data = US, group = ~group,
    fill = ~name_length, color = "white"
  ) |>
    gf_text(lat ~ long,
      label = ~name, data = States,
      color = "gray70", inherit = FALSE
    ) |>
    gf_refine(ggthemes::theme_map())
}

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