Add Grid

The Grid Layer renders a grid heatmap based on an array of points. It takes the constant size all each cell, projects points into cells. The color and height of the cell is scaled by number of points it contains.

add_grid(
  map,
  data = get_map_data(map),
  lon = NULL,
  lat = NULL,
  polyline = NULL,
  cell_size = 1000,
  extruded = TRUE,
  elevation = NULL,
  elevation_function = c("sum", "mean", "min", "max"),
  colour = NULL,
  colour_function = c("sum", "mean", "min", "max"),
  elevation_scale = 1,
  colour_range = NULL,
  legend = FALSE,
  legend_options = NULL,
  auto_highlight = FALSE,
  highlight_colour = "#AAFFFFFF",
  layer_id = NULL,
  update_view = TRUE,
  focus_layer = FALSE,
  digits = 6,
  transitions = NULL,
  brush_radius = NULL
)

Arguments

map	a mapdeck map object
data	data to be used in the layer. All coordinates are expected to be EPSG:4326 (WGS 84) coordinate system
lon	column containing longitude values
lat	column containing latitude values
polyline	optional column of data containing the polylines, if using encoded polylines
cell_size	size of each cell in meters. Default 1000
extruded	logical indicating if cells are elevated or not. Default TRUE
elevation	the height the polygon extrudes from the map. Only available if neither stroke_colour or stroke_width are supplied. Default 0
elevation_function	one of 'min', 'mean', 'max', 'sum'. IF supplied it specifies how the elevation values are calcualted. Defaults to sum.
colour	column containing numeric values to colour by.
colour_function	one of 'min', 'mean', 'max', 'sum'. If supplied it specifies how the colour values are calculated. Defaults to sum.
elevation_scale	elevation multiplier.
colour_range	vector of 6 hex colours
legend	either a logical indiciating if the legend(s) should be displayed, or a named list indicating which colour attributes should be included in the legend.
legend_options	A list of options for controlling the legend.
auto_highlight	logical indicating if the shape under the mouse should auto-highlight
highlight_colour	hex string colour to use for highlighting. Must contain the alpha component.
layer_id	single value specifying an id for the layer. Use this value to distinguish between shape layers of the same type. Layers with the same id are likely to conflict and not plot correctly
update_view	logical indicating if the map should update the bounds to include this layer
focus_layer	logical indicating if the map should update the bounds to only include this layer
digits	number of digits for rounding coordinates
transitions	list specifying the duration of transitions.
brush_radius	radius of the brush in metres. Default NULL. If supplied, the arcs will only show if the origin or destination are within the radius of the mouse. If NULL, all arcs are displayed

Details

add_grid supports POINT and MULTIPOINT sf objects

data

If the data is a simple feature object, the geometry column is automatically detected. If the sf object contains more than one geometry column and you want to use a specific one, you'll need to set the active geometry using sf::st_geometry( x ) <- "your_column" , where "your_column" is the name of the column you're activating. See ?sf::st_geometry

See also

add_hexagon

Examples

# \donttest{
## You need a valid access token from Mapbox
key <- 'abc'
set_token( key )

df <- read.csv(paste0(
'https://raw.githubusercontent.com/uber-common/deck.gl-data/master/',
'examples/3d-heatmap/heatmap-data.csv'
))

df <- df[ !is.na(df$lng ), ]

mapdeck( style = mapdeck_style("dark"), pitch = 45 ) %>%
add_grid(
  data = df
  , lat = "lat"
  , lon = "lng"
  , cell_size = 5000
  , elevation_scale = 50
  , layer_id = "grid_layer"
  , auto_highlight = TRUE
)

## using sf object
library(sfheaders)
sf <- sfheaders::sf_point( df, x = "lng", y = "lat")

mapdeck( style = mapdeck_style("dark"), pitch = 45 ) %>%
add_grid(
  data = sf
  , cell_size = 5000
  , elevation_scale = 50
  , layer_id = "grid_layer"
  , auto_highlight = TRUE
)

## using colour and elevation functions, and legends
df$val <- sample(1:10, size = nrow(df), replace = T)

mapdeck( style = mapdeck_style("dark"), pitch = 45) %>%
add_grid(
        data = df
        , lat = "lat"
        , lon = "lng"
        , layer_id = "hex_layer"
        , elevation_scale = 100
        , legend = T
        , colour_function = "max"
        , colour = "val"
)

mapdeck( style = mapdeck_style("dark"), pitch = 45) %>%
add_grid(
        data = df
        , lat = "lat"
        , lon = "lng"
        , layer_id = "hex_layer"
        , elevation_scale = 10
        , legend = T
        , elevation_function = "mean"
        , elevation = "val"
)

# }