Choosing a PRIO-GRID conversion workflow • priogridR

priogridR provides one conversion function for each common source-data format. All converters use a priogrid::pg_config() object as the source of truth for the target grid and temporal resolution.

Choose a converter

Source data	Function	Typical task
Point events or coordinate columns	`pg_from_points()`	Count events or summarize their values by cell and period
Raster layers	`pg_from_raster()`	Align continuous or categorical raster values to PRIO-GRID
Point, line, or polygon geometry	`pg_from_vector()`	Calculate counts, lengths, areas, coverage, or weighted values
NetCDF variables	`pg_from_netcdf()`	Select variables and layers before raster conversion
Values indexed by geographic units	`pg_from_table()`	Join a table to polygons and transfer the values to cells

The detailed guides are available through:

vignette("pg_from_points", package = "priogridR")
vignette("pg_from_raster", package = "priogridR")
vignette("pg_from_vector", package = "priogridR")
vignette("pg_from_netcdf", package = "priogridR")
vignette("pg_from_table", package = "priogridR")

A shared configuration

A small configuration is useful for examples and exploratory work:

config <- priogrid::pg_config(
  nrow = 18,
  ncol = 36,
  temporal_resolution = "1 year",
  start_date = as.Date("2020-12-31"),
  end_date = as.Date("2022-12-31"),
  verbose = FALSE
)

Use the default priogrid::pg_current_config() when the official global half-degree grid is required.

Common return types

Every converter accepts a return argument:

return = "data" returns a cell-level data frame;
return = "raster" returns a terra::SpatRaster; and
return = "result" returns a pg_result containing data, raster, and conversion metadata.

The default is "data". Use pg_write_result() to save tabular or raster outputs, or pass filename directly to a converter.

General advice

Check the coordinate reference system before conversion, distinguish missing values from meaningful zeros, and choose an aggregation rule that matches the meaning of the source variable. In particular, totals generally require a different transfer rule from rates, proportions, or categories.