Donut Maps with 'sf', 'ggplot2', and 'leaflet'.

DonutMap

DonutMap is an R package for drawing donut charts on static and interactive maps with sf, ggplot2, and leaflet.

Website: https://aureliennicosiaulaval.github.io/DonutMap/

The package is inspired by mtennekes/donutmaps, but starts from a simpler tidy-data interface and avoids the older odf/tmap workflow.

Online examples

The pkgdown site includes a getting-started article and a dedicated example gallery available from the Examples menu.

Installation

# From GitHub
devtools::install_github("AurelienNicosiaULaval/DonutMap")

# From this local repository
devtools::install()

Main functions

donut_map() creates a static ggplot2 map with optional coloured curved trajectories and arrows.

donut_leaflet() creates an interactive leaflet map with clickable donut segments, popups, hover labels, legends, and optional coloured curved trajectories with directional arrowheads. It builds the interactive donut symbols in EPSG:3857 by default and disables Leaflet simplification for donut polygons so sector separators stay visually regular.

donut_polygons() computes an sf polygon layer with one donut segment per non-zero location-category pair.

flow_lines() computes straight or curved origin-destination sf line geometries.

Example data

library(DonutMap)
library(ggplot2)

demo <- data.frame(
  place = rep(c("A", "B", "C"), each = 3),
  lon = rep(c(-71.35, -71.20, -71.05), each = 3),
  lat = rep(c(46.75, 46.82, 46.73), each = 3),
  category = rep(c("Walking", "Transit", "Car"), times = 3),
  value = c(10, 20, 5, 5, 15, 10, 12, 4, 9)
)

flows <- data.frame(
  from = c("A", "B"),
  to = c("B", "C"),
  trips = c(30, 10),
  flow_category = c("Transit", "Car")
)

mode_colours <- c(
  Walking = "#1b9e77",
  Transit = "#7570b3",
  Car = "#d95f02"
)

Static map

donut_map(
  demo,
  place,
  category,
  value,
  lon = lon,
  lat = lat,
  flows = flows,
  from = from,
  to = to,
  flow_value = trips,
  flow_group = flow_category,
  flow_colours = mode_colours,
  flow_curvature = 0.22,
  flow_arrow = TRUE,
  colours = mode_colours
)

Interactive map

donut_leaflet(
  demo,
  place,
  category,
  value,
  lon = lon,
  lat = lat,
  flows = flows,
  from = from,
  to = to,
  flow_value = trips,
  flow_group = flow_category,
  flow_colours = mode_colours,
  flow_curvature = 0.22,
  flow_arrow = TRUE,
  colours = mode_colours
)

Use flow_curvature = 0 for straight links, positive values for one bend direction, and negative values for the opposite direction. flow_arrow = TRUE adds directional arrows to the static and interactive trajectories. In donut_leaflet(), use flow_arrow_size to tune the arrowhead length in projected map units when the automatic size is not ideal. Use flow_group and flow_colours when the connections themselves should carry a categorical colour, for example destination municipality or flow type.

Examples and documentation

The pkgdown site includes a complete vignette with:

• simulated Québec/eastern Canada example data;
• a static ggplot2 donut map with coloured directional trajectories;
• an interactive leaflet donut map with clickable coloured trajectories;
• direct use of the sf geometry layer.

See vignette("donut-maps", package = "DonutMap") locally, or the online article:

https://aureliennicosiaulaval.github.io/DonutMap/articles/donut-maps.html.