Any simple way to remove or replace variables in a NCDataset?

[Datseris]

I have two variables x, y in a NCDataset. From them I can produce z = f(x, y). I want to add z to the dataset and remove x,y. Is there a simple way to achieve this? I would be very happy to know! I can even write a tutorial about this for the docs!

[Alexander-Barth]

Sadly, the NetCDF C API does not allow this, e.g.

Unidata/netcdf4-python#940
https://www.unidata.ucar.edu/mailing_lists/archives/netcdfgroup/1998/msg00052.html

But as you probably know, you can re-create a NetCDF file by excluding the variable that you do not want to keep.
https://alexander-barth.github.io/NCDatasets.jl/stable/dataset/#Base.write

[ctroupin]

With nco I think it's pretty simple, in particular with https://nco.sourceforge.net/nco.html#ncap2