Draw edges as glyphs

This geom draws edges as tiles with their x-position defined by the x-position of the start node, and the y-position defined by the y-position of the end node. As such it will result in a matrix layout when used in conjunction with layout_tbl_graph_matrix()

geom_edge_tile(
  mapping = NULL,
  data = get_edges(),
  position = "identity",
  mirror = FALSE,
  show.legend = NA,
  ...
)

Arguments

mapping

Set of aesthetic mappings created by ggplot2::aes() or ggplot2::aes_(). By default x, y, xend, yend, group and circular are mapped to x, y, xend, yend, edge.id and circular in the edge data.

data

The return of a call to get_edges() or a data.frame giving edges in correct format (see details for for guidance on the format). See get_edges() for more details on edge extraction.

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.

mirror

Logical. Should edge points be duplicated on both sides of the diagonal. Intended for undirected graphs. Default to FALSE

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.

...

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_edge_tile understands the following aesthetics. Bold aesthetics are automatically set, but can be overwritten.

• x

• y

• edge_fill

• edge_colour

• edge_size

• edge_alpha

• filter

Edge aesthetic name expansion

In order to avoid excessive typing edge aesthetic names are automatically expanded. Because of this it is not necessary to write edge_colour within the aes() call as colour will automatically be renamed appropriately.

See also

Other geom_edge_*: geom_edge_arc(), geom_edge_bend(), geom_edge_bundle_force(), geom_edge_bundle_minimal(), geom_edge_bundle_path(), geom_edge_density(), geom_edge_diagonal(), geom_edge_elbow(), geom_edge_fan(), geom_edge_hive(), geom_edge_link(), geom_edge_loop(), geom_edge_parallel(), geom_edge_point(), geom_edge_sf(), geom_edge_span()

Author

Thomas Lin Pedersen

Examples

require(tidygraph)
gr <- create_notable('zachary') %>%
  mutate(group = group_infomap()) %>%
  morph(to_split, group) %>%
  activate(edges) %>%
  mutate(edge_group = as.character(.N()$group[1])) %>%
  unmorph()
#> Splitting by nodes

ggraph(gr, 'matrix', sort.by = node_rank_hclust()) +
  geom_edge_tile(aes(fill = edge_group), mirror = TRUE) +
  scale_y_reverse() +
  coord_fixed() +
  labs(edge_colour = 'Infomap Cluster') +
  ggtitle("Zachary' Karate Club")