R: Link points with paths

geom_link {ggforce} | R Documentation

## 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

x, y

  The interpolated point coordinates

index

  The progression along the interpolation mapped between 0 and 1

### Author(s)

Thomas Lin Pedersen

### Examples

    # 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)

[Package ggforce version 0.1.2 Index]