ggformula: gf_contour – R documentation

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gf_contour

Formula interface to geom_contour() and geom_contour_filled()

Description

ggplot2 can not draw true 3D surfaces, but you can use geom_contour(), geom_contour_filled(), and geom_tile() to visualise 3D surfaces in 2D. To specify a valid surface, the data must contain x, y, and z coordinates, and each unique combination of x and y can appear exactly once. Contouring tends to work best when x and y form a (roughly) evenly spaced grid. If your data is not evenly spaced, you may want to interpolate to a grid before visualising, see geom_density_2d().

Usage

gf_contour(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  geom = "contour",
  stat = "contour",
  position = "identity",
  show.legend = NA,
  show.help = NULL,
  inherit = TRUE,
  environment = parent.frame()
)

gf_contour_filled(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  geom = "contour_filled",
  stat = "contour_filled",
  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`	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)`).
`...`	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`.
`xlab`	Label for x-axis. See also `gf_labs()`.
`ylab`	Label for y-axis. See also `gf_labs()`.
`title`	Title, sub-title, and caption for the plot. See also `gf_labs()`.
`subtitle`	Title, sub-title, and caption for the plot. See also `gf_labs()`.
`caption`	Title, sub-title, and caption for the plot. See also `gf_labs()`.
`geom`	The geometric object to use display the data
`stat`	The statistical transformation to use on the data for this layer, as a string.
`position`	Position adjustment, either as a string, or the result of a call to a position adjustment function.
`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.
`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.

Examples

gf_density_2d(eruptions ~ waiting, data = faithful, alpha = 0.5, color = "navy") %>%
  gf_contour(density ~ waiting + eruptions, data = faithfuld, bins = 10, color = "red")
gf_contour_filled(density ~ waiting + eruptions, data = faithfuld, bins = 10,
    show.legend = FALSE) %>%
  gf_jitter(eruptions ~ waiting, data = faithful, color = "white", alpha = 0.5,
    inherit = FALSE)

ggformula

Formula Interface to the Grammar of Graphics

v0.10.1

MIT + file LICENSE

Authors

Daniel Kaplan [aut], Randall Pruim [aut, cre]

Initial release