Add a Live Out-of-Core DuckDB / Parquet Layer (add_duckdb)

Connects glmap directly to a DuckDB connection (DBI), table name, SQL query, or .parquet / .csv file path.

Usage

add_duckdb(
  map,
  con = NULL,
  source,
  lon = "lon",
  lat = "lat",
  color = "#00d4ff",
  palette = "viridis",
  radius = 4,
  opacity = 0.85,
  where = NULL,
  max_features = 100000L,
  dynamic_viewport = TRUE,
  id = NULL,
  group = NULL,
  legend = TRUE
)

Arguments

map: A glmap widget or glmap_proxy.
con: A DBIConnection (DuckDB), or NULL if source is a .parquet/.csv file path or data.frame.
source: A table name, SQL SELECT query, .parquet file path, or data.frame to register in DuckDB.
lon: Name of the longitude column (default "lon").
lat: Name of the latitude column (default "lat").
color: Optional column name or formula (~col) to map point colors, or a fixed hex color (default "#00d4ff").
palette: Color palette name ("viridis", "plasma", "turbo", "magma", etc.).
radius: Point radius in pixels (or formula ~col).
opacity: Point opacity (0 to 1).
where: Optional SQL WHERE filter predicate string (e.g., "intensity > 50 AND category = 'Sensor'").
max_features: Maximum features streamed per viewport frame (default 100000L).
dynamic_viewport: Logical; if TRUE (default), dynamically re-queries DuckDB via httpuv as the user pans/zooms.
id: Optional layer ID.
group: Optional layer group name shown in the GPU Layer Switcher.
legend: Logical; whether to display a color legend.

Value

Updated glmap map object.

Details

Instead of loading 10M-100M+ rows into R memory, add_duckdb() pushes bounding-box viewport filters (WHERE lon BETWEEN xmin AND xmax AND lat BETWEEN ymin AND ymax) and Level-of-Detail (LOD) sampling (USING SAMPLE or deterministic stride) directly into DuckDB's vectorized execution engine, then packs the resulting slice in C++17 (cpp_pack_points_xy) and streams the GLMP binary buffer to WebGL2 over the local httpuv server on every pan/zoom!