Pass in a data frame of countries (iso2c, i23c, name) and a value column and get back a world tile grid. You don't need to have all countries in your original data set, but this is a world tile grid and only having a few countries may not make sense for the message you're trying to convey.

geom_wtg(mapping = NULL, data = NULL, border_col = "white",
  border_size = 0.125, na.rm = TRUE, show.legend = NA,
  inherit.aes = TRUE, ...)


stat_wtg(mapping = NULL, data = NULL, na.rm = NA, show.legend = NA,
  inherit.aes = TRUE, ...)




Set of aesthetic mappings created by aes() or 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.


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.


border color of the country squares, default "white"


thickness of the square country borders


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


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.


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(). These are often aesthetics, used to set an aesthetic to a fixed value, like color = "red" or size = 3. They may also be parameters to the paired geom/stat.


An object of class GeomWtg (inherits from Geom, ggproto, gg) of length 7.


Labeling world tile grids is a tricksy business and no labeling parameters are planned for this since you should think very carefully about the tradeoffs of tiny text/numbers vs readability. These charts are really only good for overviews in single-chart form or highlighting stark differences in panel-form. See the section on Computed variables for data that is available to be used as labels.
There are two special/critical aes() mappings:

  • country (so the geom knows which column to map the country names/abbrevs to)

  • fill (which column you're mapping the filling for the squares with)

Output sample

c("\nA sample of the output from geom_wtg():", "alt=\"Figure: geomwtg01.png\"\n")


Computed variables

  • x,y: the X,Y position of the tile

  • name: Country name (e.g. Afghanistan)

  • country.code: ISO2C country code abbreviation (e.g. AF)

  • iso_3166.2: Full ISO 3166 2-letter abbreviation code (e.g. ISO 3166-2:AF)

  • region: Region name (e.g. Asia)

  • sub.region: Sub-region name (e.g. Southern Asia)

  • region.code: Region code (e.g. 142)

  • sub.region.code: Sub-region code (e.g. 034)


  ctry = worldtilegrid::wtg$alpha.3,
  val = sample(1000, length(worldtilegrid::wtg$alpha.3)),
  stringsAsFactors = FALSE
) -> xdf

ggplot(xdf, aes(country = ctry, fill = val)) +
  geom_wtg() +
  geom_text(aes(label = stat(alpha.2)), stat="wtg", size=2) + # re-compute the stat to label
  coord_equal() +
  viridis::scale_fill_viridis(direction = -1) +
  labs(title = "World Tile Grid") +
  theme_minimal() +
# }