Add Deck.gl ScatterplotLayer to a mapgl::maplibre() or mapgl::mapboxgl() map using blazing fast nanoarrow::write_nanoarrow() data transfer. — addGeoArrowScatterplotLayer • deckglgeoarrow

Add Deck.gl ScatterplotLayer to a mapgl::maplibre() or mapgl::mapboxgl() map using blazing fast nanoarrow::write_nanoarrow() data transfer.

Usage

addGeoArrowScatterplotLayer(
  map,
  data,
  file,
  url,
  layer_id = "scatter",
  geom_column_name = "geometry",
  popup = NULL,
  tooltip = NULL,
  render_options = renderOptions(),
  data_accessors = dataAccessors(),
  popup_options = popupOptions(),
  tooltip_options = tooltipOptions(),
  ...
)

Arguments

map: the mapgl::maplibre() or mapgl::mapboxgl() map to add the layer to.
data: a sf (MULTI)POINT object.
file: a valid local file path to a geoarrow or geoparquet file to be added to the map. Ignored if data is supplied.
url: a URL to a remotely hosted geoarrow or geoparquet file to be added to the map. Ignored if data or file is supplied.
layer_id: the layer id.
geom_column_name: the name of the geometry column of the sf object. It is inferred automatically if only one is present.
popup: should a popup be contructed? If TRUE, will create a popup fromm all available attributes of the feature. Can also be a character vector of column names, on which case the popup will include only those columns. If a single character is supplied, then this will be shown for all features. If NULL (deafult) or FALSE, no popup will be shown.
tooltip: should a tooltip be contructed? If TRUE, will create a tooltip fromm all available attributes of the feature. Can also be a character vector of column names, on which case the tooltip will include only those columns. If a single character is supplied, then this will be shown for all features. If NULL (deafult) or FALSE, no tooltip will be shown.
render_options: a list of renderOptions
data_accessors: a list of dataAccessors
popup_options: a list of popupOptions
tooltip_options: a list of tooltipOptions
...: can be used to pass additional props and parameters to the deck.gl instance. See Details for more info.

Details

... can be used to pass additional props and parameters to the deck.gl instance for fine-tuning rendering behaviour. For example, we can pass a list called parameters with settings that control the GPU pipeline of the deck.gl instance. See https://luma.gl/docs/api-reference/core/parameters for a list of available prarmeters.

By default, all deck.gl layers passed to a maplibre() map will be drawn on top of existing ones. It is, however, possible to inject layers into the existing maplibre (base) layer stack by using render_options = renderOptions(beforeId = "<some-existing-layer-id>") which will plot the current layer underneath "<some-existing-layer-id>". See below for an example.

Examples

library(wk)
library(mapgl)

style_positron = "https://basemaps.cartocdn.com/gl/positron-gl-style/style.json"

m = maplibre(style = style_positron)

## single wk POINT
pt = wkt("POINT (0 0)")

m |>
  addGeoArrowScatterplotLayer(
    data = pt
    , layer_id = "wk_point"
  )


## wk POINT data frame
n = 5e3

pts = xy(
x = runif(n, -180, 180)
, y = runif(n, -50, 50)
, crs = 4326
)

dat = data.frame(
  id = 1:length(pts)
  , geometry = pts
)

dat$fillColor = sample(hcl.colors(n, alpha = sample(seq(0, 1, length.out = n))))
dat$lineColor = sample(
  hcl.colors(n, alpha = sample(seq(0, 1, length.out = n)), palette = "inferno")
)
dat$radius = sample.int(15, nrow(dat), replace = TRUE)
dat$lineWidth = sample.int(5, nrow(dat), replace = TRUE)

m = maplibre(
  style = style_positron
) |>
  add_navigation_control(visualize_pitch = TRUE) |>
  add_globe_control()

m |>
  addGeoArrowScatterplotLayer(
    data = dat
    , layer_id = "wk-points-layer"
    , geom_column_name = "geometry"
    , render_options = renderOptions()
    , data_accessors = dataAccessors(
      getRadius = "radius"
      , getFillColor = "fillColor"
      , getLineWidth = "lineWidth"
      , getLineColor = "lineColor"
    )
    , popup = TRUE
    , popup_options = popupOptions(anchor = "bottom-right")
    , tooltip = TRUE
    , tooltip_options = tooltipOptions(anchor = "top-left")
  )


## same as above, but using `beforeId` to inject layer into base layer stack
m |>
  addGeoArrowScatterplotLayer(
    data = dat
    , layer_id = "wk-points-layer-before-water"
    , geom_column_name = "geometry"
    , render_options = renderOptions(beforeId = "water")
    , data_accessors = dataAccessors(
      getRadius = "radius"
      , getFillColor = "fillColor"
      , getLineWidth = "lineWidth"
      , getLineColor = "lineColor"
    )
    , popup = TRUE
    , popup_options = popupOptions(anchor = "bottom-right")
    , tooltip = FALSE
    , tooltip_options = tooltipOptions(anchor = "top-left")
  )


## remote parquet file
## paste url together so CRAN check doesn't complain
base_url = "https://raw.githubusercontent.com/geoarrow/"
data_url = "geoarrow-data/v0.2.0/natural-earth/files/natural-earth_cities_native.parquet"
url = paste0(base_url, data_url)

m |>
  addGeoArrowScatterplotLayer(
    url = url
    , layer_id = "parquet-layer"
    , geom_column_name = "geometry"
    , data_accessors = dataAccessors(
      getRadius = 10
      , getFillColor = '#ff000090'
      , getLineColor = '#000000ff'
    )
    , tooltip = TRUE
  )