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Collect time-varying (non-static) PRIO-GRID data

Source: R/build_priogrid.R
read_pg_timevarying.Rd

Loads all time-varying variables and returns them either as a data.table or as a list of rasters. See pgvariables for available variables.

Usage

read_pg_timevarying(
  config = NULL,
  version = NULL,
  type = "05deg_yearly",
  spatial_hash = NULL,
  temporal_hash = NULL,
  years = NULL,
  start_date = NULL,
  end_date = NULL,
  pgids = NULL,
  extent = NULL,
  variables = NULL,
  as_raster = FALSE,
  test = FALSE,
  overwrite = FALSE,
  verify_checksums = FALSE
)

Arguments

config

A pg_config object for custom data, or NULL (default) for the official release.

version

Character string specifying PRIOGRID version (release mode only).

type

Character string specifying release type. Default: "05deg_yearly".

spatial_hash

Character string with 6-character spatial hash (custom only).

temporal_hash

Character string with 6-character temporal hash (custom only).

years

Integer vector of years to keep. NULL (default) keeps all. Prunes hive partitions on the year column.

start_date, end_date

Date (or Date-coercible) bounds on measurement_date (inclusive). NULL (default) leaves the respective bound open.

pgids

Integer vector of PRIO-GRID cell ids to keep. NULL (default) keeps all cells.

extent

Numeric c(xmin, xmax, ymin, ymax) in lon/lat (EPSG:4326), or a terra SpatExtent in the grid's native CRS; resolved to the pgids it covers and unioned with pgids. For non-4326 configs the lon/lat box is reprojected automatically. Requires terra. NULL (default) applies no spatial filter.

variables

Character vector of time-varying variable columns to return (in addition to pgid, measurement_date, year). NULL (default) returns all variables.

as_raster

Logical. If TRUE, returns list of SpatRasters. If FALSE (default), returns data.table.

test

Logical. If TRUE, returns coverage summary data.frame.

overwrite

Logical. If FALSE (default) and cached file exists, returns cached data. If TRUE, rebuilds from individual variables.

verify_checksums

Logical. If TRUE, verifies checksums of cached files against stored MD5 values. Default FALSE.

Value

data.table with pgid + measurement_date as rows and variables as columns, or list of terra SpatRasters if as_raster=TRUE, or coverage test data.frame if test=TRUE

Details

The mode is determined by the config argument:

  • config = NULL (default): loads from the official release (downloads if needed).

  • config = pg_config(...): loads from custom data built with that config.

Examples

if (FALSE) { # \dontrun{
  # Load official release as data.table
  pg_dt <- read_pg_timevarying()

  # Load specific official release
  pg_dt <- read_pg_timevarying(version = "3.0.1")

  # Load custom data
  cfg <- pg_config(nrow = 180, ncol = 360)
  pg_dt <- read_pg_timevarying(config = cfg)

  # Subset: two years, a bounding box, and one variable
  pg_dt <- read_pg_timevarying(version = "3.0.1", years = c(2010, 2011),
                               extent = c(10, 12, 50, 52), variables = "cru_tmp")
} # }