centroid-labels.R

library(mapgl)
library(tidycensus)

tarrant_age <- get_acs(
  geography = "tract",
  variables = "B01002_001",
  state = "TX",
  county = "Tarrant",
  geometry = TRUE
)

palette <- interpolate_palette(
  tarrant_age,
  column = "estimate", 
  palette = viridisLite::cividis
)

maplibre(
  style = carto_style("positron"), 
  bounds = tarrant_age
) |> 
  add_fill_layer(
    id = "age-layer",
    source = tarrant_age,
    fill_color = palette$expression,
    fill_opacity = 0.5
  ) |> 
  turf_center_of_mass(
    layer_id = "age-layer",
    source_id = "label-source"
  ) |> 
  add_symbol_layer(
    id = "symbols",
    source = "label-source",
    text_field = concat("Tract: ", get_column("GEOID"), 
                        "\nMedian: ", get_column("estimate")), 
    min_zoom = 13
  )