geom_sugarbag

geom_sugarbag() provides a convenient way to create tesselated hexagon maps using the sugarbag algorithm.

geom_sugarbag(
  mapping = NULL,
  data = NULL,
  stat = "sugarbag",
  position = "identity",
  hex_size = 0.2,
  na.rm = FALSE,
  ...
)

Arguments

mapping

Set of aesthetic mappings created by 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, either as a ggproto Geom subclass or as a string naming the stat stripped of the stat_ prefix (e.g. "count" rather than "stat_count")

position

Position adjustment, either as a string naming the adjustment (e.g. "jitter" to use position_jitter), or the result of a call to a position adjustment function. Use the latter if you need to change the settings of the adjustment.

hex_size

Default is 0.2. Units are degrees, corresponding to the diameter of the hexagons. See ?allocate.

na.rm

If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.

...

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.

Details

Create a sugarbag hex map

The sugarbag algorithm creates a hexagon tile map from spatial polygons. It represents each polygon with a hexagon, which is placed close to the polygon's centroid while also maintaining its spatial relationship to a focal point.

If geom_sugarbag() is used to make a map of Australia, the capital cities will be used as focal points. For non-Australian maps, a single focal point will be inferred from the data, as the centroid with the smallest total distance to its three nearest neighbours. To specify focal points manually, construct your hexagon grid manually -- see ?allocate.

Examples

# \donttest{
library(ggplot2)
# Map of Tasmanian local govt areas using built-in data
 tas_lga %>%
  ggplot(aes(fill = lga_name_2016)) +
  geom_sf(alpha = 0.1) +
  geom_sugarbag(aes(geometry = geometry)) +
  theme(legend.position = "none")

  
# Map of SIDS data from North Carolina
if (requireNamespace("sf", quietly = TRUE)) {
nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)

ggplot(nc,
  aes(fill = AREA)) +
  geom_sf(alpha = 0.1) +
  geom_sugarbag(aes(geometry = geometry))
}
#> Warning: Computation failed in `stat_sugarbag()`
#> Caused by error in `mutate()`:
#> ℹ In argument: `across(everything(), ~na_if(.x, 0))`.
#> Caused by error in `across()`:
#> ! Can't compute column `sf_id`.
#> Caused by error in `na_if()`:
#> ! Can't convert `y` <double> to match type of `x` <character>.

# }

Arguments

Details

See also

Examples