Spike map (heights at country centroids) — spike

The classic "population spikes" display: a triangular spike at each country centroid whose height encodes the value. Like bubble_map() it is the honest idiom for totals, with a different visual trade-off: spikes overplot less in dense regions (Europe, the Caribbean) because they only grow upward. Uses the polygon backend, so it needs only maps.

Usage

spike_map(
  data,
  height,
  max_height = 20,
  width = 1.6,
  color = "#B2182B",
  alpha = 0.65
)

Arguments

data: A country-level frame with iso3c and the height column.
height: The column controlling spike height (unquoted).
max_height: Height of the tallest spike, in degrees of latitude (default 20).
width: Base width of each spike, in degrees of longitude (default 1.6).
color: Spike colour (default a warm red).
alpha: Spike fill transparency.

Value

A ggplot object.

Examples

# \donttest{
if (requireNamespace("maps", quietly = TRUE)) {
  spike_map(countryatlas::world_snapshot$countries, population)
}

# }