Computes the spatial variance of a 2D or 3D field. This is the wrapping around the native cdfmean operator assuming its usage is:
cdfmean IN-file IN-var T|U|V|F|W **[imin imax jmin jmax kmin kmax]**
... **[-full]** [-var] [-zeromean]
CliMAF optional arguments are the ones surrounded with ‘**’.
If a spatial window is specified, the spatial variance is computed only in this window. See also:
- ccdfvar_profile for getting a vertical profile of spatial variance for each level for 3D fields
References : http://www.drakkar-ocean.eu/tools
Provider / contact : climaf at meteo dot fr for the wrapping
Inputs (in the order of CliMAF call):
- any dataset (but only one)
Mandatory argument:
- pos_grid : position of cdfvar on the C-grid : T|U|V|F|W
Optional arguments:
- imin, imax, jmin, jmax, kmin, kmax : for defining spatial windows
- opt : may be used to pass key -full (compute the mean for full steps, instead of default partial steps)
Required files: Files mesh_hgr.nc, mesh_zgr.nc, mask.nc must be in the current directory (use function fixed_fields() for that; see example below).
Outputs:
- main output : a netcdf file (variable : var_3D_cdfvar)
Climaf call example:: For more examples which are systematically tested, see cdftools.py
>>> # How to get required files for cdftools cdfmean binary
>>> fixed_fields('ccdfvar',
... ('mask.nc', '/data/climaf/${project}/${model}/ORCA1_mesh_mask.nc'),
... ('mesh_hgr.nc','/data/climaf/${project}/${model}/ORCA1_mesh_hgr.nc'),
... ('mesh_zgr.nc','/data/climaf/${project}/${model}/ORCA1_mesh_zgr.nc'))
>>> duo=ds(simulation="PRE6CPLCr2alb", variable="uo", period="199807", realm="O") # some dataset, with whatever variable
>>> my_cdfvar=ccdfvar(duo,pos_grid='U')
>>> cfile(my_cdfvar) # to compute the spatial variance and get a filename with the result
>>> my_cdfvar2=ccdfvar(duo,pos_grid='U',opt='-full')
>>> cfile(my_cdfvar2)
>>> my_cdfvar3=ccdfvar(duo,pos_grid='U',imin=100,imax=102,jmin=117,jmax=118,kmin=1,kmax=2)
>>> cfile(my_cdfvar3)
Implementation: The operator is implemented as a binary using cdftools cdfmean operator.