Compute Spatial Weights for BLISA

Builds queen (nearby) and distance-decay (diffuse) spatial weight matrices from a bin-level sf object, excluding isolated bins and optionally excluding low-cell bins. A second-pass isolation check further removes bins that become isolated after the initial subset.

Usage

computeSpatialWeights(
  bins,
  bin_size = 50,
  dmax = 250,
  min_cells = 1,
  n_cells_col = NA
)

Arguments

bins

An sf object of spatial bins.

bin_size

Numeric. Bin spacing used to define queen adjacency (1.2 * bin_size radius).

dmax

Numeric. Maximum distance for diffuse-mode neighbours.

min_cells

Integer. Minimum cell count for a bin to be included. Ignored when n_cells_col = NA.

n_cells_col

Character or NA. Column name in bins holding per-bin cell counts. Set to NA to skip cell-count filtering (default).

Value

A list with:

queen_wt

Spatial weights list for nearby (queen) mode.

dist_wt

Spatial weights list for diffuse (distance-decay) mode.

keep_idx_queen

Integer indices of bins used in queen-mode Moran.

keep_idx_dist

Integer indices of bins used in diffuse-mode Moran.

isolate_idx_queen

Integer indices of original queen-mode isolates.

isolate_idx_dist

Integer indices of original diffuse-mode isolates.

low_cell_idx

Integer indices of bins excluded for low cell counts.

queen_nb_full

Full (unsubset) neighbour list for nearby mode, indexed over all bins.

dist_nb_full

Full (unsubset) neighbour list for diffuse mode, indexed over all bins.

Examples

if (FALSE) { # \dontrun{
set.seed(42)
pts  <- sf::st_as_sf(
  data.frame(x = runif(300, 0, 1000), y = runif(300, 0, 1000)),
  coords = c("x", "y"), crs = NA
)
bins <- sf::st_sf(
  geometry = sf::st_make_grid(pts, cellsize = 100,
                              what = "polygons", square = FALSE)
)
sw <- computeSpatialWeights(bins, bin_size = 100, dmax = 300)
names(sw)
} # }