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Reference lines – horizontal, vertical, and diagonal.

Source: R/gf_functions.R
gf_lines.Rd

These functions create layers that display lines described i various ways. Unlike most of the plotting functions in ggformula, these functions do not take a formula as input for describing positional attributes of the plot.

Usage

gf_abline(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  slope,
  intercept,
  color,
  linetype,
  linewidth,
  alpha,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  show.legend = NA,
  show.help = NULL,
  inherit = FALSE,
  environment = parent.frame()
)

gf_hline(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  yintercept,
  color,
  linetype,
  linewidth,
  alpha,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  position = "identity",
  show.legend = NA,
  show.help = NULL,
  inherit = FALSE,
  environment = parent.frame()
)

gf_vline(
  object = NULL,
  gformula = NULL,
  data = NULL,
  ...,
  xintercept,
  color,
  linetype,
  linewidth,
  alpha,
  xlab,
  ylab,
  title,
  subtitle,
  caption,
  position = "identity",
  show.legend = NA,
  show.help = NULL,
  inherit = FALSE,
  environment = parent.frame()
)

gf_coefline(object = NULL, coef = NULL, model = NULL, ...)

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

Must be NULL.

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.

color

A color or a formula used for mapping color.

linetype

A linetype (numeric or "dashed", "dotted", etc.) or a formula used for mapping linetype.

linewidth

A numerical line width or a formula used for mapping linewidth.

alpha

Opacity (0 = invisible, 1 = opaque).

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().

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. 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.

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.

position

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.

xintercept, yintercept, slope, intercept

Parameters that control the position of the line. If these are set, data, mapping and show.legend are overridden.

coef

A numeric vector of coefficients.

model

A model from which to extract coefficients.

See also

ggplot2::geom_abline(), ggplot2::geom_vline(), ggplot2::geom_hline()

Examples

mtcars2 <- df_stats(wt ~ cyl, data = mtcars, median_wt = median)
gf_point(wt ~ hp, size = ~wt, color = ~cyl, data = mtcars) |>
  gf_abline(slope = ~0, intercept = ~median_wt, color = ~cyl, data = mtcars2)


gf_point(wt ~ hp, size = ~wt, color = ~cyl, data = mtcars) |>
  gf_abline(slope = 0, intercept = 3, color = "green")


# avoid warnings by using formulas:

gf_point(wt ~ hp, size = ~wt, color = ~cyl, data = mtcars) |>
  gf_abline(slope = ~0, intercept = ~3, color = "green")


gf_point(wt ~ hp, size = ~wt, color = ~cyl, data = mtcars) |>
  gf_hline(yintercept = ~median_wt, color = ~cyl, data = mtcars2)


gf_point(mpg ~ hp, color = ~cyl, size = ~wt, data = mtcars) |>
  gf_abline(color = "red", slope = ~ - 0.10, intercept = ~ 35)


gf_point(mpg ~ hp, color = ~cyl, size = ~wt, data = mtcars) |>
  gf_abline(
    color = "red", slope = ~slope, intercept = ~intercept,
    data = data.frame(slope = -0.10, intercept = 33:35)
  )


# We can set the color of the guidelines while mapping color in other layers
gf_point(mpg ~ hp, color = ~cyl, size = ~ wt, data = mtcars) |>
  gf_hline(color = "navy", yintercept = ~ c(20, 25), data = NA) |>
  gf_vline(color = "brown", xintercept = ~ c(200, 300), data = NA)
#> Warning: `aes_string()` was deprecated in ggplot2 3.0.0.
#> ℹ Please use tidy evaluation idioms with `aes()`.
#> ℹ See also `vignette("ggplot2-in-packages")` for more information.
#> ℹ The deprecated feature was likely used in the ggformula package.
#>   Please report the issue at
#>   <https://github.com/ProjectMOSAIC/ggformula/issues>.


# If we want to map the color of the guidelines, it must work with the
# scale of the other colors in the plot.
gf_point(mpg ~ hp, size = ~wt, data = mtcars, alpha = 0.3) |>
  gf_hline(color = ~"horizontal", yintercept = ~ c(20, 25), data = NA) |>
  gf_vline(color = ~"vertical", xintercept = ~ c(100, 200, 300), data = NA)


gf_point(mpg ~ hp, size = ~wt, color = ~ factor(cyl), data = mtcars, alpha = 0.3) |>
  gf_hline(color = "orange", yintercept = ~ 20) |>
  gf_vline(color = ~ c("4", "6", "8"), xintercept = ~ c(80, 120, 250), data = NA)


gf_point(mpg ~ hp, size = ~wt, color = ~ factor(cyl), data = mtcars, alpha = 0.3) |>
  gf_hline(color = "orange", yintercept = ~ 20) |>
  gf_vline(color = c("green", "red", "blue"), xintercept = ~ c(80, 120, 250),
    data = NA)


# reversing the layers requires using inherit = FALSE
gf_hline(color = "orange", yintercept = ~ 20) |>
  gf_vline(color = ~ c("4", "6", "8"), xintercept = ~ c(80, 120, 250), data = NA) |>
  gf_point(mpg ~ hp,
    size = ~wt, color = ~ factor(cyl), data = mtcars, alpha = 0.3,
    inherit = FALSE
  )