Build an LPJmL/WHEP spatial covariate function — make_lpjml

Creates a function(centroids_sf, year) suitable for APIs that accept a spatial covariate density, such as build_constant_territory_series(). The covariate is built from prepared WHEP/LPJmL spatialization inputs, either from a local input_dir or from pinned WHEP spatialization inputs when input_dir = NULL.

Usage

make_lpjml_covariate(
  input_dir = NULL,
  years = NULL,
  weighting = c("total_cropland", "crop_pattern"),
  item_prod_code = NULL,
  cft_mapping = whep::cft_mapping
)

Arguments

input_dir: Directory holding prepared WHEP/LPJmL input parquets. If NULL, the function reads pinned spatialization inputs via whep_read_file().
years: Integer vector of years to retain. If NULL, all years present in the required input are used.
weighting: Either "total_cropland", "crop_pattern", or a custom function(centroids_sf, year). A custom function is returned unchanged.
item_prod_code: FAOSTAT/WHEP production item code. Required when weighting = "crop_pattern".
cft_mapping: Mapping from WHEP item codes to CFT/LUH2 types. Defaults to cft_mapping.

Value

A function function(centroids_sf, year) returning non-negative density values aligned to centroids_sf.

Examples

# A custom covariate function is returned unchanged, ready to plug into
# build_constant_territory_series(). Here a uniform (area-weighting) density:
uniform <- function(centroids_sf, year) rep(1, nrow(centroids_sf))
covariate <- make_lpjml_covariate(weighting = uniform)
identical(covariate, uniform)
#> [1] TRUE

# The "total_cropland" and "crop_pattern" modes instead read prepared
# WHEP/LPJmL spatialization parquets from `input_dir` (or pinned inputs).