Re: [ferret_users] Transform grid

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Yun,
        The easy way to achieve this is by using RESHAPE function. For
details about this function, please have a look at the user manual,
Ch3 Sec2.3.23.

  RESHAPE function takes two arguments : first one is the original 
variable (to be reshaped) and second one is a variable on the destination
grid (after reshaping). In your case the Z-axis to be changed to T-axis,
so a procedure as follows will work.

     use HADISST_1_1_SST_2004.nc
     define axis/t=16-JAN-2004:15-DEC-2004:`365.2425/12`/units=days\
                 /T0=31-DEC-2003  tmonth  ! monthly time axis for 2004
     ! now define a variable on the destination grid.
     let dest_grid = x[gx=sst,d=1]*0 + y[gy=sst,d=1]*0 + t[gt=tmonth]*0  
     ! RESHAPE it....
     let sst_mon = RESHAPE(sst_mon,dest_grid)
     ! assign proper title and units
     set var/title="Hadi Monthly SST 2004"/units="Deg_C" sst_mon
     ! save to a NetCDF file for future use
     sp rm -f Hadi_mon_sst_2004.nc
     save/file=Hadi_mon_sst_2004.nc/APPEND sst_mon

Hope this helps..if you find any problem with this method, please let me know.

Regards,

Jaison

On Mon, 26 Feb 2007 Yun.Li@xxxxxxxx wrote:

> 
> Dear All,
> 
> I have a copy of monthly HADISST_1_1_SST_2004.nc as follows. 
> 
> yes? use HADISST_1_1_SST_2004.nc
> yes? show data
>      currently SET data sets:
>     1> ./HADISST_1_1_SST_2004.nc  (default)
>  name     title                             I         J         K
> L
>  T        Fake time                        1:12      ...       ...
> ...
>  LON      Longitude                        1:360     ...       ...
> ...
>  LAT      Latitude                         1:180     ...       ...
> ...
>  SST      SST                              1:360     1:180     1:12
> ...
> 
> 
> Ferret cannot draw the plots properly due to the incorrect grid settings
> (K =1:12). Could you please help me to transform the grid as the correct
> format (L=1:12)? That is,
> 
> > show data
>      currently SET data sets:
>     1> ./HADISST_1_1_SST_2004.nc  (default)
>  name     title                             I         J         K
> L
>  SST      SST                              1:360     1:180     ...
> 1:12
> 
> 
> Regards,
> 
> Yun Li
> CSIRO, Australia
>