Compose a resistance surface from multiple raster layers — compose

Aligns one or more terra::SpatRaster layers to a common template (CRS, resolution, extent) and combines them into a single resistance raster using a specified rule. Intended for building resistance_rast inputs for geodesic tessellations.

Usage

compose_resistance(
  ...,
  template = NULL,
  mask = NULL,
  method = c("multiply", "add", "max"),
  resample_method = c("bilinear", "near"),
  na_policy = c("propagate", "ignore")
)

Arguments

...: One or more terra::SpatRaster layers. All layers must represent strictly positive resistance values.
template: Optional terra::SpatRaster defining the target grid (CRS, resolution, extent). Defaults to the first layer.
mask: Optional mask applied after alignment. Can be a terra::SpatRaster, terra::SpatVector, or sf polygon.
method: How to combine layers: "multiply" (default), "add", or "max".
resample_method: Resampling method used when aligning layers: "bilinear" for continuous resistance, "near" for categorical rasters.
na_policy: How to treat NA values: "propagate" makes any NA propagate to the output; "ignore" drops NAs (neutral element for the chosen method).

Value

A terra::SpatRaster resistance surface on the template grid.

Examples

if (FALSE) { # \dontrun{
R <- compose_resistance(slope_resistance, landcover_resistance, method = "multiply")
R <- add_barriers(R, rivers_sf, permeability = "semi", cost_multiplier = 20, width = 30)
out <- weighted_voronoi_domain(points_sf, "w", boundary_sf, distance = "geodesic",
                               resistance_rast = R)
} # }