Show nodes as POINTs in geographical space

This geom is equivalent in functionality to ggplot2::geom_sf() for POINT geometries and allows for plotting of nodes in their geographical space in different shapes, colours and sizes.

geom_node_sf(
  mapping = NULL,
  data = get_sf_nodes(),
  position = "identity",
  show.legend = NA,
  ...
)

Arguments

mapping

Set of aesthetic mappings created by ggplot2::aes() or ggplot2::aes_(). By default geometry is mapped to the geometry in the node data.

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)).

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.

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.

You can also set this to one of "polygon", "line", and "point" to override the default legend.

...

Other arguments passed on to layer()'s params argument. These arguments broadly fall into one of 4 categories below. Notably, further arguments to the position argument, or aesthetics that are required can not be passed through .... Unknown arguments that are not part of the 4 categories below are ignored.

• Static aesthetics that are not mapped to a scale, but are at a fixed value and apply to the layer as a whole. For example, colour = "red" or linewidth = 3. The geom's documentation has an Aesthetics section that lists the available options. The 'required' aesthetics cannot be passed on to the params. Please note that while passing unmapped aesthetics as vectors is technically possible, the order and required length is not guaranteed to be parallel to the input data.

• When constructing a layer using a stat_*() function, the ... argument can be used to pass on parameters to the geom part of the layer. An example of this is stat_density(geom = "area", outline.type = "both"). The geom's documentation lists which parameters it can accept.

• Inversely, when constructing a layer using a geom_*() function, the ... argument can be used to pass on parameters to the stat part of the layer. An example of this is geom_area(stat = "density", adjust = 0.5). The stat's documentation lists which parameters it can accept.

• The key_glyph argument of layer() may also be passed on through .... This can be one of the functions described as key glyphs, to change the display of the layer in the legend.

Aesthetics

geom_node_sf understand the following aesthetics.

• alpha

• colour

• shape

• size

• filter

See also

Other geom_node_*: geom_node_arc_bar(), geom_node_circle(), geom_node_point(), geom_node_range(), geom_node_text(), geom_node_tile(), geom_node_voronoi()

Author

Lorena Abad

Examples

library(tidygraph)

if (require("sfnetworks", quietly = TRUE)) {
  gr <- sfnetworks::as_sfnetwork(roxel)
  ggraph(gr, 'sf') +
    geom_node_sf(aes(color = centrality_betweenness()))
}