writeCDF doesn't allow force_v4

[bocinsky]

Hi there,

The terra:::.write_cdf function accepts dots, and checks to see whether force_v4 is included among them, passing it on to ncdf4::nc_create. However, force_v4 is also passed on to ncdf4::ncvar_def, which throws an error. I'm not sure about the appropriate solution, but perhaps force_v4 should be an explicit parameter of the terra::writeCDF (and terra:::.write_cdf) function?

Reprex below. Thanks for all you do!

f <- system.file("ex/elev.tif", package="terra")
r <- terra::rast(f)
fname <- paste0(tempfile(), ".nc")

# Works
rr <- terra::writeCDF(r, fname, overwrite=TRUE, varname="alt",
               longname="elevation in m above sea level", unit="m")

# Error because ncdf4::ncvar_def doesn't accept dots
rr <- terra::writeCDF(r, fname, overwrite=TRUE, varname="alt",
               longname="elevation in m above sea level", unit="m", force_v4 = TRUE)
#> Error in ncdf4::ncvar_def(name = vars[i], units = units[i], dim = list(xdim, : unused argument (force_v4 = TRUE)

^{Created on 2023-02-09 with reprex v2.0.2}

[rhijmans]

Thank you very much. Not sure what I was thinking, but fixed now.