Re: [ferret_users] sample_dimension in ferret

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

Hi Hella,

The other attribute that's needed is "cf_role", as an attribute on a 
variable which will identify the station (or trajectory, or whatever the 
feature type is, in general). Your file doesn't seem to have a variable 
that is a station id. This is described in the CF conventions but it 
looks like we need to add this information to the Ferret documentation 
about Discrete Sampling Geometries files.

-Ansley


On 3/8/2017 8:07 AM, Hella Riede wrote:
> Hello ferreters,
>
>
> I checked out the ferret documentation website about discrete 
> geometries 
> http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/data-set-basics/2-8-discrete-geometries-datasets-1, 
> especially about the attribute 'sample_dimension'.
>
> Based on 
> http://cfconventions.org/cf-conventions/v1.6.0/cf-conventions.html#_contiguous_ragged_array_representation_of_time_series, 
> I made a simple dataset, see attachments, containing the 
> 'sample_dimension' attribute.
>
> When I load this simple example into ferret, I don't get the 
> observations on the X axis and the instance axis ('station') in E 
> direction as described on the ferret website above, but rather two X 
> grids instead, see output below.
>
> Any idea why? Is the 'dsg_file.nc' dataset used in the ferret example 
> available somewhere to better understand the structure?
>
> I am not sure if 'obs' should be the sum of all observations of all 
> stations which 'rowsize' will then divide up per station, or if 'obs' 
> should be the maximum length per 'station'.
>
> Thanks in advance!
>
> Best wishes,
> Hella
> on FERRET v7.022 (beta/debug)
>
>
>
>
> yes? use ragged.nc
> yes? sh da
>       currently SET data sets:
>      1> ./ragged.nc  (default)
>   name     title                             I         J K         L
>   LON      station longitude                1:3       ... ...       ...
>   LAT      station latitude                 1:3       ... ...       ...
>   ROWSIZE  number of observations for this  1:3       ... ...       ...
>   TEMP     temperature                      1:11      ... ...       ...
>   yes? sh grid temp
>      GRID GNN2
>   name       axis              # pts   start end                 subset
>   OBS       X                   11 r   1 11                  full
>   normal    Y
>   normal    Z
>   normal    T
> yes? sh grid rowsize
>      GRID GNN1
>   name       axis              # pts   start end                 subset
>   STATION   X                    3 r   1 3                   full
>   normal    Y
>   normal    Z
>   normal    T