add_contour_layer {deckgl}

Add a contour layer to the deckgl widget

Description

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.

Usage

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.

See Also

https://deck.gl/#/documentation/deckgl-api-reference/layers/contour-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