Add a contour layer to the deckgl widget

The ContourLayer renders contour lines for a given threshold and cell size. Internally it implements Marching Squares algorithm to generate contour line segments and feeds them into LineLayer to render lines.

add_contour_layer(
  deckgl,
  data = NULL,
  properties = list(),
  ...,
  id = "contour-layer"
)

Arguments

deckgl: A deckgl widget object.
data: The url to fetch data from or a data object.
properties: A named list of properties with names corresponding to the properties defined in the deckgl-api-reference for the given layer class. The properties parameter can also be an empty list. In this case all props must be passed as named arguments.
...: Named arguments that will be added to the properties object. Identical parameters are overwritten.
id: The unique id of the layer.

Examples

## @knitr contour-layer
data("sf_bike_parking")

contours <- list(
  use_contour_definition(
    threshold = 1,
    color = c(255, 0, 0),
    stroke_width = 2
  ),
  use_contour_definition(
    threshold = 5,
    color = c(0, 255, 0),
    stroke_width = 3
  ),
  use_contour_definition(
    threshold = 15,
    color = c(0, 0, 255),
    stroke_width = 5
  )
)

properties <- list(
  contours = contours,
  cellSize = 200,
  elevationScale = 4,
  getPosition = ~lng + lat
)

deck <- deckgl(zoom = 10.5, pitch = 30) %>%
  add_contour_layer(data = sf_bike_parking, properties = properties) %>%
  add_control("Contour Layer") %>%
  add_basemap()

if (interactive()) deck

Arguments

See also

Examples