geom_offset_bezier: Offset-bezier Curve with Variable-Width
In houyunhuang/ggvwline: Extending 'ggplot2' to Draw Variable-Width Lines

Description Usage Arguments Aesthetics See Also Examples

View source: R/geom-offset-bezier.R

The main curve is described by x/y position points and offset bezier curves are calculated to the left and right of the main curve at the specified widths.

geom_offset_bezier(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  open = TRUE,
  width_units = "cm",
  width_fun = "bezier",
  width_shape = -1,
  rep = FALSE,
  step_fn = nSteps(100),
  linejoin = "round",
  lineend = "butt",
  mitre_limit = 4,
  debug = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

`mapping`	Set of aesthetic mappings created by `aes()` or `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.
`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)`).
`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.
`...`	Other arguments passed on to `layer()`. These are often aesthetics, used to set an aesthetic to a fixed value, like `colour = "red"` or `size = 3`. They may also be parameters to the paired geom/stat.
`open`	a logical value indicating whether to connect the last location back to the first location to produce a closed line.
`width_units`	the units of line, detail see `unit`.
`width_fun`	either "bezier" (default) or "spline" to specifying the width function: `bezier`: `BezierWidth` `spline`: `widthSpline`
`width_shape`	the shape parameter for the width spline.
`rep`	a logical value indicating whether to repeat the widths along the full length of the line.
`step_fn`	function called to generate steps in t when rendering.
`linejoin`	the line join style; one of "round" (default), "mitre", or "bevel".
`lineend`	the line ending style; one of "round" (default), "mitre", "butt", or "square".
`mitre_limit`	a numeric that controls when a mitre join is converted to a bevel join or a mitre ending is converted to a square ending.
`debug`	a logical value indicating whether to produce graphical debugging output.
`na.rm`	If `FALSE`, the default, missing values are removed with a warning. If `TRUE`, missing values are silently removed.
`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.
`inherit.aes`	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, e.g. `borders()`.

geom_offset_bezier() understands the following aesthetics (required aesthetics are in bold):

x
y
alpha
colour
dist
fill
linetype
size
width

offsetBezierGrob, BezierWidth, widthSpline.

df <- data.frame(
  x = c(.2, .4, .6, .8),
  y = c(-.05, .05, -.05, .05),
  width = c(0.5, 1, 1.5, 2)
  )

ggplot(df, aes(x, y, width = width)) + geom_offset_bezier()
ggplot(df, aes(x, y, width = width)) + geom_offset_bezier(lineend = "round")
ggplot(df, aes(x, y, width = width)) +
  geom_offset_bezier(colour = "black", fill = NA, debug = TRUE)