Add a ranking of the features in view — add_view

Adds a panel listing the features in view with the highest (or lowest) values, updated as the map is panned and zoomed. Each entry shows the value, a bar on the scale of the whole layer and the feature's rank among all features; clicking on a name moves the map to it.

Usage

add_view_ranking(
  map,
  layer_id,
  column,
  name_column,
  label = column,
  n = 5,
  order = c("desc", "asc"),
  title = NULL,
  unit = "features",
  locale = "en-US",
  digits = 1,
  prefix = "",
  suffix = "",
  position = "top-right",
  width = 240,
  color = NULL,
  highlight_color = "#1f2328",
  collapsible = TRUE,
  collapsed = NULL,
  labels = context_labels()
)

Arguments

map: A map created with mapgl::maplibre() or mapgl::mapboxgl().
layer_id: ID of the layer to summarise: a polygon layer (such as mapgl::add_fill_layer()) or a point layer (such as mapgl::add_circle_layer() or mapgl::add_symbol_layer()). Its source must be an sf object or inline GeoJSON added in R; vector tile sources are not supported.
column: Name of the numeric column to rank by.
name_column: Column with the feature names to list.
label: Name of the variable shown in the panel. Defaults to column.
n: Number of features to list.
order: "desc" (the default) lists the highest values first; "asc", the lowest.
title: Title of the panel. NULL (the default) uses the ranking_highest or ranking_lowest label.
unit: Name for the features, shown as "14 of 528 unit".
locale: Locale for number formatting, such as "en-US" or "es-AR".
digits: Number of decimals for values. Values of a million or more are abbreviated, such as 12.4M.
prefix, suffix: Text added before and after each value, such as "$" or "%".
position: Corner for the panel: one of "top-left", "top-right", "bottom-left" or "bottom-right".
width: Width of the panel in pixels.
color: Color for the bars. NULL (the default) uses the layer's own color scale when it is an interpolate() or step_expr() on column, and blue otherwise.
highlight_color: Color of the outline drawn around a feature when hovering over its name.
collapsible: If TRUE, adds a button to collapse the panel down to its title and the first name.
collapsed: Whether the panel starts collapsed. NULL (the default) starts collapsed on maps narrower than 480 pixels, such as on phones.
labels: Panel texts, as returned by context_labels().

Value

The modified map object.

Details

Which features count as "in view" follows the same rules as add_view_summary().

Examples

if (FALSE) { # \dontrun{
library(mapgl)

maplibre(center = c(-64, -38.5), zoom = 3.4) |>
  add_fill_layer(
    id = "deptos",
    source = ar_departments,
    fill_color = interpolate(
      column = "growth",
      values = c(-10, 0, 10),
      stops = c("#b2182b", "#f7f7f7", "#2166ac")
    )
  ) |>
  add_view_ranking(
    layer_id = "deptos",
    column = "growth",
    name_column = "department",
    label = "Population growth 2022-2035",
    unit = "departments",
    suffix = "%"
  )
} # }