Put a downloaded raster's layers into the order they were requested

Copernicus returns layers in the NetCDF's own order, which is alphabetical by variable code and has nothing to do with the order they were asked for. Column names are assigned from vars, so the two have to be reconciled before naming or the names land on the wrong layers.

Usage

order_layers(x, vars)

Arguments

x

a SpatRaster read from a Copernicus download

vars

variable codes, in the order they were requested

Value

x, with one layer per requested code, in that order

Details

That failure is silent and severe: requesting c("SST", "SSS") sends c("thetao", "so"), gets back so then thetao, and would label salinity as temperature and temperature as salinity with nothing to indicate it. Matching by name rather than position is the whole point of this function.

Layer names

Three-dimensional variables come back as thetao_depth=0.494025, so the depth suffix is stripped before matching. Two-dimensional ones such as mlotst and zos carry no suffix.

A code appearing on more than one layer means the depth range spanned several model levels. That is reported as such, rather than left to be caught later by a column count that cannot say which variable caused it.