Re: [ferret_users] Possible bug in Ferret 6.7 vs 6.64

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi-
Sending this also to the Users List - further thoughts on a better solution for this issue:

On 2/14/2012 12:16 AM, Hein Zelle wrote:

Hi Ansley Manke,

Hi all,
Gary has had a chance to test a beta version of Ferret which
includes some further work on this issue of creating the grids for
variables, and he's able to read the datset successfully in Ferret.
This will be included in the next Ferret release, and will keep us
going until the extra-dimensional Ferret is ready to go.

Given our previous problems with WRF output files (problem introduced
in 6.7.1, fixed in 6.7.2)  I'd very much like to test this beta
version before it's released.

Kind regards,

     Hein

I'm working on a somewhat better solution.  What's done in the beta executable is to relax the requirement (introduced in 6.7) that dimensions have the same direction in all grids in a dataset.  This means that for these datasets having the lat_vertices and lon_vertices variables with dimensions  (j,i,v),  things look like this:

version 6.64:

yes? show dat
     currently SET data sets:
    1> ./thkcello_fx_CCSM4_lgm_r0i0p0.nc  (default)
 name     title                             I         J         K         L
 LAT      latitude coordinate              1:320     1:384     ...       ...
 LON      longitude coordinate             1:320     1:384     ...       ...
 LAT_VERTICES
                                           1:4       1:320     1:384     ...
 LON_VERTICES
                                           1:4       1:320     1:384     ...
 THKCELLO Ocean Model Cell Thickness       1:320     1:384     1:60      ...
 

version 6.72:

yes? show dat
     currently SET data sets:
    1> ./thkcello_fx_CCSM4_lgm_r0i0p0.nc  (default)

name     title                             I         J         K         L
 LAT      latitude coordinate              1:320     ...       1:384     ...
 LON      longitude coordinate             1:320     ...       1:384     ...
 LAT_VERTICES
                                           1:320     1:4       1:384     1:320
 LON_VERTICES
                                           1:320     1:4       1:384     1:320
 THKCELLO Ocean Model Cell Thickness       1:320     ...       1:384     1:60
 
version 6.724: (back to the way it looked in v6.64)

yes? sh dat
     currently SET data sets:
    1> ./thkcello_fx_CCSM4_lgm_r0i0p0.nc  (default)
 name     title                             I         J         K         L
 LAT      latitude coordinate              1:320     1:384     ...       ...
 LON      longitude coordinate             1:320     1:384     ...       ...
 LAT_VERTICES
                                           1:4       1:320     1:384     ...
 LON_VERTICES
                                           1:4       1:320     1:384     ...
 THKCELLO Ocean Model Cell Thickness       1:320     1:384     1:60      ...


Which means that we can use the data field, but to make use of lon_vertices and lat_vertices, we'd have to work around those grids in Ferret scripts.  We have an idea to define a permuted grid for the variables that have the extra dimension beyond the x dimension, so that for the next official release, Ferret should create grids that will look like this, with the "v" dimension along an abstract Z axis.

version 6.73 (yet to come)

yes? sh dat
     currently SET data sets:
    1> ./thkcello_fx_CCSM4_lgm_r0i0p0.nc  (default)
 name     title                             I         J         K         L
 LAT      latitude coordinate              1:320     1:384     ...       ...
 LON      longitude coordinate             1:320     1:384     ...       ...
 LAT_VERTICES
                                           1:320     1:384     1:4       ...
 LON_VERTICES
                                           1:320     1:384     1:4       ...
 THKCELLO Ocean Model Cell Thickness       1:320     1:384     1:60      ...