geodesics {leaflet.extras}

Add Geodesic Lines & Circles

Description

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 htmltools::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"))