Add Polygon — add_polygon • mapdeck

The Polygon Layer renders filled and/or stroked polygons.

add_polygon(
  map,
  data = get_map_data(map),
  polyline = NULL,
  stroke_colour = NULL,
  stroke_width = NULL,
  stroke_opacity = NULL,
  fill_colour = NULL,
  fill_opacity = NULL,
  elevation = NULL,
  tooltip = NULL,
  auto_highlight = FALSE,
  elevation_scale = 1,
  highlight_colour = "#AAFFFFFF",
  light_settings = list(),
  layer_id = NULL,
  id = NULL,
  palette = "viridis",
  na_colour = "#808080FF",
  legend = FALSE,
  legend_options = NULL,
  legend_format = 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
polyline	optional column of `data` containing the polylines, if using encoded polylines
stroke_colour	variable of `data` or hex colour for the stroke. If used, `elevation` is ignored. If using a hex colour, use either a single value, or a column of hex colours on `data`
stroke_width	width of the stroke in meters. If used, `elevation` is ignored. Default 1.
stroke_opacity	Either a string specifying the column of `data` containing the opacity of each shape, or a single value in [0,255], or [0, 1), to be applied to all the shapes. Default 255. If a hex-string is used as the colour, this argument is ignored and you should include the alpha on the hex string
fill_colour	column of `data` or hex colour for the fill colour. If using a hex colour, use either a single value, or a column of hex colours on `data`
fill_opacity	Either a string specifying the column of `data` containing the opacity of each shape, or a single value in [0,255], or [0, 1), to be applied to all the shapes. Default 255. If a hex-string is used as the colour, this argument is ignored and you should include the alpha on the hex string
elevation	the height the polygon extrudes from the map. Only available if neither `stroke_colour` or `stroke_width` are supplied. Default 0
tooltip	variable of `data` containing text or HTML to render as a tooltip
auto_highlight	logical indicating if the shape under the mouse should auto-highlight
elevation_scale	elevation multiplier.
highlight_colour	hex string colour to use for highlighting. Must contain the alpha component.
light_settings	list of light setting parameters. See light_settings
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
id	an id value in `data` to identify layers when interacting in Shiny apps.
palette	string or matrix. String will be one of `colourvalues::colour_palettes()`. A matrix must have at least 5 rows, and 3 or 4 columns of values between [0, 255], where the 4th column represents the alpha. You can use a named list to specify a different palette for different colour options (where available), e.g. list(fill_colour = "viridis", stroke_colour = "inferno")
na_colour	hex string colour to use for NA values
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.
legend_format	A list containing functions to apply to legend values. See section legend
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_polygon supports POLYGON and MULTIPOLYGON 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

transitions

The transitions argument lets you specify the time it will take for the shapes to transition from one state to the next. Only works in an interactive environment (Shiny) and on WebGL-2 supported browsers and hardware.

The time is in milliseconds

Available transitions for polygon

list( polygon = 0, fill_colour = 0, stroke_colour = 0, stroke_width = 0, elevation = 0 )

legend

The legend_options can be used to control the appearance of the legend. This should be a named list, where the names are one of

css - a string of valid css for controlling the appearance of the legend
title - a string to use for the title of the legend
digits - number to round the legend values to

If the layer allows different fill and stroke colours, you can use different options for each. See examples in add_arc.

The legend_format can be used to control the format of the values in the legend. This should be a named list, where the names are one of

fill_colour
stroke_colour

depending on which type of colouring the layer supports.

The list elements must be functions to apply to the values in the legend.

id

The id is returned to your R session from an interactive shiny environment by observing layer clicks. This is useful for returning the data.frame row relating to the cliked shape.

From within a shiny server you would typically use observeEvent({input$map_arc_click}), where 'map' is the map_id supplied to mapdeckOutput(), and 'arc' is the layer you are clicking on

Examples

# \donttest{

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

library(geojsonsf)

sf <- geojsonsf::geojson_sf("https://symbolixau.github.io/data/geojson/SA2_2016_VIC.json")

mapdeck(
  style = mapdeck_style('dark')
) %>%
  add_polygon(
    data = sf
    , layer = "polygon_layer"
    , fill_colour = "SA2_NAME16"
)
#> default

df <- melbourne  ## data.frame with encoded polylnies
df$elevation <- sample(100:5000, size = nrow(df))
df$info <- paste0("<b>SA2 - </b><br>",df$SA2_NAME)

mapdeck(
  style = mapdeck_style('dark')
  , location = c(145, -38)
  , zoom = 8
  ) %>%
  add_polygon(
    data = df
    , polyline = "geometry"
    , layer = "polygon_layer"
    , fill_colour = "SA2_NAME"
    , elevation = "elevation"
    , tooltip = 'info'
    , legend = T
  )
#> default

# }