Add Geodesic Lines & Circles — geodesics • leaflet.extras

A geodesic line is the shortest path between two given positions on the earth surface. It's based on Vincenty's formulae implemented by Chris Veness for highest precision.

Add Lat/Long to a Geodesic Polyline.

Adds a Great Circle to the map.

Usage

addGeodesicPolylines(
  map,
  lng = NULL,
  lat = NULL,
  layerId = NULL,
  group = NULL,
  steps = 10,
  wrap = TRUE,
  stroke = TRUE,
  color = "#03F",
  weight = 5,
  opacity = 0.5,
  dashArray = NULL,
  smoothFactor = 1,
  noClip = FALSE,
  popup = NULL,
  popupOptions = NULL,
  label = NULL,
  labelOptions = NULL,
  options = pathOptions(),
  highlightOptions = NULL,
  icon = NULL,
  showMarker = FALSE,
  showStats = FALSE,
  statsFunction = NULL,
  markerOptions = NULL,
  data = getMapData(map)
)

addLatLng(map, lat, lng, layerId = NULL)

addGreatCircles(
  map,
  lat_center = NULL,
  lng_center = NULL,
  radius,
  layerId = NULL,
  group = NULL,
  steps = 10,
  wrap = TRUE,
  stroke = TRUE,
  color = "#03F",
  weight = 5,
  opacity = 0.5,
  dashArray = NULL,
  smoothFactor = 1,
  noClip = FALSE,
  popup = NULL,
  popupOptions = NULL,
  label = NULL,
  labelOptions = NULL,
  options = pathOptions(),
  highlightOptions = NULL,
  icon = NULL,
  fill = TRUE,
  showMarker = FALSE,
  showStats = FALSE,
  statsFunction = NULL,
  markerOptions = NULL,
  data = getMapData(map)
)

Arguments

map: a map widget object created from leaflet()
lat, lng: lat/lng to add to the Geodesic
layerId: the layer id
group: the name of the group the newly created layers should belong to (for clearGroup and addLayersControl purposes). Human-friendly group names are permitted–they need not be short, identifier-style names. Any number of layers and even different types of layers (e.g. markers and polygons) can share the same group name.
steps: Defines how many intermediate points are generated along the path. More steps mean a smoother path.
wrap: Wrap line at map border (date line). Set to "false" if you want lines to cross the dateline (experimental, see noWrap-example on how to use)
stroke: whether to draw stroke along the path (e.g. the borders of polygons or circles)
color: stroke color
weight: stroke width in pixels
opacity: stroke opacity (or layer opacity for tile layers)
dashArray: a string that defines the stroke dash pattern
smoothFactor: how much to simplify the polyline on each zoom level (more means better performance and less accurate representation)
noClip: whether to disable polyline clipping
popup: a character vector of the HTML content for the popups (you are recommended to escape the text using htmlEscape() for security reasons)
popupOptions: A Vector of popupOptions to provide popups
label: a character vector of the HTML content for the labels
labelOptions: A Vector of labelOptions to provide label options for each label. Default NULL
options: a list of extra options for tile layers, popups, paths (circles, rectangles, polygons, ...), or other map elements
highlightOptions: Options for highlighting the shape on mouse over.
icon: the icon(s) for markers; an icon is represented by an R list of the form list(iconUrl = "?", iconSize = c(x, y)), and you can use icons() to create multiple icons; note when you use an R list that contains images as local files, these local image files will be base64 encoded into the HTML page so the icon images will still be available even when you publish the map elsewhere
showMarker: Should the nodes/center points be visualized as Markers?
showStats: This will create an L.Control with some information on the geodesics
statsFunction: A custom JS function to be showed in the info control
markerOptions: List of options for the markers. See markerOptions
data: the data object from which the argument values are derived; by default, it is the data object provided to leaflet() initially, but can be overridden
lat_center, lng_center: lat/lng for the center
radius: in meters
fill: whether to fill the path with color (e.g. filling on polygons or circles)

Examples

berlin <- c(52.51, 13.4)
losangeles <- c(34.05, -118.24)
santiago <- c(-33.44, -70.71)
tokio <- c(35.69, 139.69)
sydney <- c(-33.91, 151.08)
capetown <- c(-33.91, 18.41)
calgary <- c(51.05, -114.08)
hammerfest <- c(70.67, 23.68)
barrow <- c(71.29, -156.76)

df <- as.data.frame(rbind(hammerfest, calgary, losangeles, santiago, capetown, tokio, barrow))
names(df) <- c("lat", "lng")

leaflet(df) %>%
  addProviderTiles(providers$CartoDB.Positron) %>%
  addGeodesicPolylines(
    lng = ~lng, lat = ~lat, weight = 2, color = "red",
    steps = 50, opacity = 1
  ) %>%
  addCircleMarkers(df,
    lat = ~lat, lng = ~lng, radius = 3, stroke = FALSE,
    fillColor = "black", fillOpacity = 1
  )


## for more examples see
# browseURL(system.file("examples/geodesic.R", package = "leaflet.extras"))