Is something changed in "from_c_grid_dataset" for time-varying depth in Parcels 3 version?

[RomanIMMSP]

Dear Parcels developers,
thank you for your continuous improvement of the Parcels. I tried to move to the Parcels 3 version and found a lot of changes. Most of them I can manage myself but several questions remain.

First of all, when I try to run the code that worked on the previous version I have an error. The code and error follow. I would be very grateful if someone could advise me.

filenames = {'U': {'lon': path+'coordinates.nc', 'lat': path+'coordinates.nc', 'depth': path+'U/U_001.nc', 'data': path+'U/U_0*.nc'}, 
             'V': {'lon': path+'coordinates.nc', 'lat': path+'coordinates.nc', 'depth': path+'V/V_001.nc', 'data': path+'V/V_0*.nc'},
             'W': {'lon': path+'coordinates.nc', 'lat': path+'coordinates.nc', 'depth': path+'W/W_001.nc', 'data': path+'W/W_0*.nc'},
             'z_w': {'lon': path+'coordinates.nc', 'lat': path+'coordinates.nc', 'depth': path+'W/W_001.nc', 'data': path+'/Zw/Zw_0*.nc'}}
variables = {'U': 'u', 'V': 'v', 'W': 'w', 'z_w': 'z_w'}
indices = {'U': {'lon': range(0, 1441), 'lat': range(0, 429)},
           'V': {'lon': range(0, 1441), 'lat': range(0, 429)}}
dimensions = {'U': {'lon': 'lon_psi', 'lat': 'lat_psi', 'depth': 'not_yet_set', 'time': 'ocean_time'},
              'V': {'lon': 'lon_psi', 'lat': 'lat_psi', 'depth': 'not_yet_set', 'time': 'ocean_time'},
              'W': {'lon': 'lon_psi', 'lat': 'lat_psi', 'depth': 'not_yet_set', 'time': 'ocean_time'},
              'z_w': {'lon': 'lon_psi', 'lat': 'lat_psi', 'depth': 's_w', 'time': 'ocean_time'}}

fieldset = FieldSet.from_c_grid_dataset(filenames, variables, dimensions, indices={'depth': range(0,30)},  
           allow_time_extrapolation=False, time_periodic=delta(days=1095))

fieldset.U.set_depth_from_field(fieldset.z_w)
fieldset.V.set_depth_from_field(fieldset.z_w)
fieldset.W.set_depth_from_field(fieldset.z_w)

Error message: "depth dimension has a wrong format. It should be [tdim, zdim, ydim, xdim]"

Thanks in advance!

[erikvansebille]

Thanks for raising this, @RomanIMMSP. Could you provide me (via email?) a subset of your data where this error can be seen? That is the easiest way for me to check/fix the issue

[RomanIMMSP]

The solution by @erikvansebille is in the following changes

indices = {'lon': range(0, 1441), 'lat': range(0, 429), 'depth': range(0,30)}
fieldset = FieldSet.from_c_grid_dataset(filenames, variables, dimensions, indices=indices,  
           allow_time_extrapolation=False, time_periodic=delta(days=1095))