In martinjhnhadley/oidnChaRts: Utility Functions For htmlwidget Visualisations

Geolines Map

Our sample dataset is included in the library, data_geo_lines_plot and comprises a set of send-receive coordinates. The geo_lines_plot function requires a dataset with at least the following columns:

start.latitude
start.longitude
end.latitude
end.longitude

library(oidnChaRts)
head(data_geo_lines_plot)

Hat tip to http://personal.tcu.edu/kylewalker/interactive-flow-visualization-in-r.html for the geospheres library which computes great circles.

Leaflet

Basic Example

The minimal number of arguments required for geo_line_map are as follows:

library(leaflet)
geo_lines_plot(data_geo_lines_plot, 
              library = "leaflet")

There are additional arguments that may control the line.options and termini.options (the dots at each end of the geo_line)

geo_lines_plot(data_geo_lines_plot, 
              library = "leaflet",
              line.options = list(weight = 3))

The leaflet map produced by geo_lines_plot can be used in pipe chains like any other leaflet map:

geo_lines_plot(data_geo_lines_plot, 
              library = "leaflet",
              line.options = list(weight = 3)) %>%
  addProviderTiles("Stamen.Watercolor")

Tooltips

The geo_lines_plot function has been designed for tooltips to be easily added to the lines of termini, in the example below a popup will show when a geo_line is clicked.

label_journey <- function(start.location = NA, end.location = NA){
  paste0(
    "<p>start: ", start.location,
    "</p>",
    "<p>end: ", end.location
  )
}
geo_lines_plot(data_geo_lines_plot, 
              library = "leaflet",
              line.popup = ~label_journey(start.location, end.location),
              line.options = list(weight = 3)) %>%
  addProviderTiles("Stamen.Watercolor")

Choropleth from points

Our sample dataset is included in the library, data_geo_points and comprises a set of coordinates . The geo_lines_plot function requires a dataset with at least the following columns: