Prepare a geodesic context for repeated runs — prepare_geodesic

Precomputes the domain mask, aligned resistance handling, transition object, and multisource graph representation (when applicable) for repeated geodesic tessellation workflows.

Usage

prepare_geodesic_context(
  boundary_sf,
  res = 20,
  close_mask = TRUE,
  close_iters = 1,
  resistance_rast = NULL,
  dem_rast = NULL,
  use_tobler = TRUE,
  tobler_v0_kmh = 6,
  tobler_a = 3.5,
  tobler_b = 0.05,
  min_speed_kmh = 0.25,
  anisotropy = c("none", "terrain"),
  uphill_factor = 1,
  downhill_factor = 1,
  geodesic_engine = c("classic", "multisource")
)

Arguments

boundary_sf: An sf POLYGON/MULTIPOLYGON defining the domain.
res: Numeric. Raster resolution in CRS units (e.g. metres).
close_mask: Logical. If TRUE, applies a morphological closing to the raster mask.
close_iters: Integer. Number of closing iterations.
resistance_rast: Optional SpatRaster giving movement resistance (>0).
dem_rast: Optional SpatRaster providing elevation or resistance surface.
use_tobler: Logical; if TRUE, apply Tobler's hiking function to convert slope into isotropic movement cost.
tobler_v0_kmh: Base walking speed on flat terrain (km/h).
tobler_a: Tobler exponential slope coefficient.
tobler_b: Tobler slope multiplier.
min_speed_kmh: Minimum allowed speed to avoid infinite costs.
anisotropy: Character. One of "none" or "terrain".
uphill_factor: Numeric > 0. Additional uphill movement penalty when anisotropy = "terrain".
downhill_factor: Numeric > 0. Relative ease of downhill movement when anisotropy = "terrain".
geodesic_engine: Character. One of "classic" or "multisource".

Value

A prepared geodesic context object for repeated geodesic allocation.