Re: [ferret_users] Trying to visualize data on cubed-sphere grid

[Steve Hankin <steven.c.hankin@xxxxxxxx>]

Hi Gary,

Any luck with this?  I neglected to mention that the RESHAPE technique should work if the size, 777602, is either Nlat*Nlon (cell point locations) or (Nlat+1)*(Nlon+1) (cell edge locations).  For RESHAPE to work in a single step the ordering of data within the 1D array needs to be with the longitudes as the fastest moving index.  If latitude is the fastest moving, then you'll need to throw a TRANSPOSE_XY(coord) into the game.

    - Steve

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On 4/8/2013 8:24 AM, Steve Hankin wrote:

Gary,

Ferret expects the CF auxiliary coordinates to be on the same 2D horizontal coordinate system as the data variables.   Have a look at using the RESHAPE function to wrap the 1D coordinate arrays onto a 2D coordinate system.
http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/variables-xpressions/XPRESSIONS#_VPINDEXENTRY_335

    - Steve

On 4/6/2013 7:27 AM, Gary Strand wrote:

I'm playing around with some data that's on a cubed-sphere grid, and am wondering if the description of the grid is causing the usual "Y coord field lies in different plane from data to be plotted" error when using the "shade ts,lon,lat" command.

The data of interest and the longitudes and latitudes are all described as one-dimensional vectors, i.e., a 1-D array of N points:

yes? use test.nc 
yes? show data
     currently SET data sets:
    1> ./test.nc  (default)
 name     title                             I         J         K         L         M         N
 TS       Surface temperature (radiative)  1:777602  ...       ...       1:1       ...       ...
 LAT      latitude                         1:777602  ...       ...       ...       ...       ...
 LON      longitude                        1:777602  ...       ...       ...       ...       …

and 'ncdump -h' shows:

prompt> ncdump -h test.nc | egrep "(lon|lat|TS)"

        float TS(time, ncol) ;

                TS:units = "K" ;

                TS:long_name = "Surface temperature (radiative)" ;

                TS:cell_methods = "time: mean" ;

        double lat(ncol) ;

                lat:long_name = "latitude" ;

                lat:units = "degrees_north" ;

                lat:axis = "Y" ;

        double lon(ncol) ;

                lon:long_name = "longitude" ;

                lon:units = "degrees_east" ;

                lon:axis = "X" ;

Giving lon and lat the appropriate "axis" attributes doesn't change anything about how FERRET sees the data.

Any suggestions appreciated!

Gary Strand
strandwg@xxxxxxxx