Learn R Programming

ggforce (version 0.1.1)

geom_link: Link points with paths

Description

This set of geoms makes it possible to connect points using straight lines. Before you think geom_segment and geom_path, these functions have some additional tricks up their sleeves. geom_link connects two points in the same way as geom_segment but does so by interpolating multiple points between the two. An additional column called index is added to the data with a sequential progression of the interpolated points. This can be used to map color or size to the direction of the link. geom_link2 uses the same syntax as geom_path but interpolates between the aesthetics given by each row in the data.

Usage

stat_link(mapping = NULL, data = NULL, geom = "path", position = "identity", na.rm = FALSE, show.legend = NA, n = 100, inherit.aes = TRUE, ...)
stat_link2(mapping = NULL, data = NULL, geom = "path_interpolate", position = "identity", na.rm = FALSE, show.legend = NA, n = 100, inherit.aes = TRUE, ...)
geom_link(mapping = NULL, data = NULL, stat = "link", position = "identity", arrow = NULL, lineend = "butt", na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, n = 100, ...)
geom_link2(mapping = NULL, data = NULL, stat = "link2", position = "identity", arrow = NULL, lineend = "butt", na.rm = FALSE, show.legend = NA, inherit.aes = TRUE, n = 100, ...)
geom_link0(mapping = NULL, data = NULL, stat = "identity", position = "identity", ..., arrow = NULL, lineend = "butt", na.rm = FALSE, show.legend = NA, inherit.aes = TRUE)

Arguments

mapping
Set of aesthetic mappings created by aes or aes_. If specified and inherit.aes = TRUE (the default), is combined with the default mapping at the top level of the plot. You only need to supply mapping if there isn't a mapping defined for the plot.
data
A data frame. If specified, overrides the default data frame defined at the top level of the plot.
geom,
stat Override the default connection between geom_arc and stat_arc.
position
Position adjustment, either as a string, or the result of a call to a position adjustment function.
na.rm
If FALSE (the default), removes missing values with a warning. If TRUE silently removes missing values.
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.
n
The number of points to create for each segment
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.
...
other arguments passed on to layer. There are three types of arguments you can use here:
  • Aesthetics: to set an aesthetic to a fixed value, like color = "red" or size = 3.
  • Other arguments to the layer, for example you override the default stat associated with the layer.
  • Other arguments passed on to the stat.
stat
The statistical transformation to use on the data for this layer, as a string.
arrow
specification for arrow heads, as created by arrow()
lineend
Line end style (round, butt, square)

Aesthetics

geom_link understand the following aesthetics (required aesthetics are in bold):
  • x
  • y
  • xend
  • yend
  • color
  • size
  • linetype
  • alpha
  • lineend
geom_link2 understand the following aesthetics (required aesthetics are in bold):
  • x
  • y
  • color
  • size
  • linetype
  • alpha
  • lineend

Computed variables

Examples

Run this code
# Lets make some data
lines <- data.frame(
  x = c(5, 12, 15, 9, 6),
  y = c(17, 20, 4, 15, 5),
  xend = c(19, 17, 2, 9, 5),
  yend = c(10, 18, 7, 12, 1),
  width = c(1, 10, 6, 2, 3),
  colour = letters[1:5]
)

ggplot() + geom_link(aes(x = x, y = y, xend = xend, yend = yend,
                         colour = colour, alpha = ..index..,
                         size = ..index..),
                     data = lines)

ggplot() + geom_link2(aes(x = x, y = y, colour = colour, size = width,
                          group = 1),
                      data = lines, lineend = 'round', n = 500)

Run the code above in your browser using DataLab