Temporal weighted tessellation — weighted_voronoi

Runs weighted tessellation across a sequence of time-specific point datasets and returns a stack of allocation rasters, with optional polygons and summaries per time step.

Usage

weighted_voronoi_time(
  points_list,
  weight_col,
  boundary_sf,
  time_index = NULL,
  distance = c("euclidean", "geodesic"),
  geodesic_engine = c("multisource", "classic"),
  res = 20,
  resistance_list = NULL,
  dem_list = NULL,
  keep_polygons = FALSE,
  keep_summaries = TRUE,
  prepared = NULL,
  verbose = TRUE,
  ...
)

Arguments

points_list: A non-empty list of sf POINT objects, one per time step.
weight_col: Character. Name of the weight column present in each element of points_list.
boundary_sf: An sf POLYGON/MULTIPOLYGON defining the domain.
time_index: Optional character vector of time labels. Defaults to names(points_list) if present, otherwise "t1", "t2", etc.
distance: Character. One of "euclidean" or "geodesic".
geodesic_engine: Character. Geodesic engine to use when distance = "geodesic".
res: Numeric. Raster resolution in CRS units (e.g. metres).
resistance_list: Optional list of resistance rasters, either length 1 (reused for all times) or the same length as points_list.
dem_list: Optional list of DEM rasters, either length 1 (reused for all times) or the same length as points_list.
keep_polygons: Logical. If TRUE, return polygons for each time step.
keep_summaries: Logical. If TRUE, return summaries for each time step.
prepared: Optional prepared geodesic context created by prepare_geodesic_context() for repeated compatible geodesic runs.
verbose: Logical. If TRUE, prints progress.
...: Additional arguments passed to weighted_voronoi_domain().

Value

A list containing:

allocations: A terra::SpatRaster with one allocation layer per time step.
time_index: Character vector of time labels.
change_map_first_last: A terra::SpatRaster indicating whether allocation changed between the first and last time step (1 = changed, 0 = unchanged).
persistence: A terra::SpatRaster indicating whether each cell retained the same allocation across all time steps (1 = persistent, 0 = changed at least once).
polygons: Optional list of sf polygon outputs by time.
summaries: Optional list of summary tables by time.

Details

This first implementation assumes a static boundary and runs each time step independently. Time-varying weights, point locations, and resistance/DEM surfaces are supported by supplying separate inputs for each time step.