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Validate a reference fabric before building from it

Source: R/check_reference_input.R
check_reference_input.Rd

A build inherits whatever its reference asserts. Two classes of input damage are silent at read time yet destroy the result:

Usage

check_reference_input(
  reference_gpkg,
  layer = "flowpaths",
  id = "flowpath_id",
  toid = "flowpath_toid",
  min_resolved = 0.9,
  strict = TRUE
)

Arguments

reference_gpkg

Path to a reference fabric GeoPackage.

layer

Flowpaths layer name. Default "flowpaths".

id, toid

Identifier and downstream-identifier column names.

min_resolved

Minimum share of non-terminal toid values that must name an existing id. Terminals (toid 0 or NA) are excluded from the denominator, since they legitimately point nowhere.

strict

If TRUE (default) a failure raises an error; if FALSE it warns and returns the findings.

Value

Invisibly, a list with ok and one entry per check.

Details

  • Truncated identifiers. GeoPackage MEDIUMINT columns are 32-bit (OFTInteger). A 14-digit NHD-HR identifier written into one wraps modulo 2^32, so flowpath_toid becomes a negative or unrelated number while flowpath_id (64-bit INTEGER) survives. Nothing errors; the topology is simply gone.

  • Unresolvable topology. When flowpath_toid names identifiers that are not present in flowpath_id, aggregation finds no connected reaches and degenerates to one flowpath per reach: the fabric is produced, passes its invariants, and is silently unaggregated.

Both are cheap to detect and expensive to discover afterwards, so this runs before a build rather than after.

Examples

if (FALSE) { # \dontrun{
check_reference_input("conus_reference.gpkg")
} # }