nctoolkit relies on Climate Data Operators (CDO) as its computational backend. This is a high-powered command line tool for manipulating and analyzing climate model data. You can read more about CDO on their website.
nctoolkit is designed as a stand alone package and users will require no understanding of CDO to use it. However, people with knowledge of CDO may want to use the
to use CDO methods directly.
Using CDO commands¶
If you want to apply a CDO command in nctoolkit, all you need to do is remove the beginning and end, i.e. ‘cdo’ and the file names.
So, a typical CDO command looks like this:
cdo yearmean infile.nc outfile.nc
If we wanted to use this in nctoolkit, we would just do this:
If the CDO command is an ensemble method that takes multiple files as input and produces one, you will need to specify that it is an ensemble method, as follows:
ds.cdo_command("ensmean", ensemble = True)
Using NCO commands¶
nctoolkit also allows you to apply NCO commands to datasets using the
nco_command method. You just need to remove the two file names from the command you want to apply.
So, the following command:
ncks -v kd_490 -d lat,40.0,70.0 -d lon,-20.0,15.0 infile.nc outfile.nc
ds.nco_command("ncks -v kd_490 -d lat,40.0,70.0 -d lon,-20.0,15.0")