Which source and archive produced a fetched object

Every access function stamps its result with where the values came from, and this reads it back. The tag is short and stable — "copernicus:...", "fvcom:GOM3", "hycom:GLBv53X", "ccmp:v03.1" — naming the source and the particular archive or dataset within it.

Usage

source_of(x)

Arguments

x

an object from accessEnvDat(), accessFVCOM(), accessHYCOM() or accessCCMP()

Value

the source tag, or NA if the object carries none — which is the case for anything built by hand or produced before this was recorded

Why this exists

The four sources deliberately share variable names, so an SST column means the same quantity whichever produced it and everything downstream works unchanged. That is the point of the design and also its hazard: the column name alone cannot say whether a value came from a global reanalysis, a regional coastal model, or an independent global model, and those are not the same number.

The package already records provenance where a value's origin is ambiguous — fill_satellite_gaps() writes a <var>_source column, and a derived BOTS returns BOTS_depth. This extends the same habit to the thing that varies most: which model the value came from at all.

See also

matchData(), which carries this into <var>_source columns

Examples

if (FALSE) { # \dontrun{
env <- accessHYCOM(vars = "BOTS", dates = "2010-06-15", bounding_box = bb)
source_of(env)
#> [1] "hycom:GLBv53X"
} # }