Re: [ferret_users] inconsistent data grids: File needs axis attributes on coordinate variables indicating correct direction

[Patrick Brockmann <patrick.brockmann@xxxxxxxxxxxx>]

Hi all,

I have investigated a little bit more on the internal ferret mechanism that leads to produce this error. 

**ERROR: inconsistent data grids: File needs axis attributes on coordinate variables indicating correct directions

Starting from an example given by the CF convention description from the folowing paragraph

https://cfconventions.org/Data/cf-conventions/cf-conventions-1.9/cf-conventions.html#cell-boundaries

I have reproduced the error from a very simple exemple.

$ cat notok.cdl

netcdf notok {
dimensions:
       jmax = 1 ;
       imax = 1 ;
       nv = 4 ;
variables:
       double lat(jmax, imax) ;
               lat:long_name = "latitude" ;
               lat:units = "degrees_north" ;
               lat:bounds = "bounds_lat" ;
       double lon(jmax, imax) ;
               lon:long_name = "longitude" ;

ferret complains about some inconsistent data grid and missing axis attributes.

use notok.nc 
          *** NOTE: 
          *** NOTE: Could not adjust grid for variable mask_T 
**ERROR: inconsistent data grids: File needs axis attributes on coordinate variables indicating correct directions

Stranger, if I change the name of the dimension, then the file

is read. I have not been able to fix this by adding a direction attribute as requested.

The file is simple as:

$ ncdump notok.nc
netcdf notok { 
dimensions: 
       y_grid_T = 1 ; 
       x_grid_T = 1 ; 
       nvertex_grid_T = 4 ; 
variables: 
       double bounds_lat_grid_T(y_grid_T, x_grid_T, nvertex_grid_T) ; 
       double bounds_lon_grid_T(y_grid_T, x_grid_T, nvertex_grid_T) ; 
       byte mask_T(y_grid_T, x_grid_T) ; 
&n