SDF file has no discernable X coordinate

[Don Hooper]

Remi Meynadier,

The units attribute on the coordinate variable for the X axis must
have one of these four values to be discerned to be an X axis:
"degrees_east",  "degree_east",  "degrees_E",  "degree_E"
This is per the standard of the day, back when this code was written
for GrADS.  Change "east" to "north" and "E" to "N" for Y axis discernment.

I don't know why your DDF failed, as that is not my area of expertise; however,
possibilities include "did you use the "open" command on your DDF" and
"is the NetCDF in the current directory, as your DSET indicates".

-Hoop

> From owner-GRADSUSR at LIST.CINECA.IT  Tue Nov 20 16:03:04 2007
>
> There are 5 messages totalling 260 lines in this issue.
>
> Topics of the day:
>
>   3. SDF file has no discernable X coordinate
>
> ----------------------------------------------------------------------
>
> Date:    Tue, 20 Nov 2007 16:48:43 +0100
> From:    Remi Meynadier <remi.meynadier at AERO.JUSSIEU.FR>
> Subject: SDF file has no discernable X coordinate
>
> Hi folks
>
> i want to open a netcdf file (see the ncdump -h below) but with no success :
>
> i've tried :
>
> -sdfopen myfile.nc :
> GRads answered :
> Scanning self-describing file:  ISBA_Evap_exp2_2006.nc
> SDF file has no discernable X coordinate.
>
> - i've created a ddf file (see below)
> GRads:
> "Scanning description file:  isba.ddf
> NetCDF Error (nc_open): Unable to open file"
>
> Does someone have an idea of what's going on ?
>
> Thanks in advance
> Remi
>
>
>
> netcdf ISBA_Evap_exp2_2006 {
> dimensions:
>         lon = 101 ;
>         lat = 51 ;
>         z = 3 ;
>         time = UNLIMITED ; // (365 currently)
> variables:
>         float lon(lon) ;
>                 lon:valid_range = -20.f, 30.f ;
>                 lon:associate = "lon" ;
>                 lon:units = "degrees East" ;
>                 lon:long_name = "lon" ;
>         float lat(lat) ;
>                 lat:valid_range = -5.f, 20.f ;
>                 lat:associate = "lat" ;
>                 lat:units = "degrees North" ;
>                 lat:long_name = "lat" ;
>         int z(z) ;
>                 z:valid_range = 1, 3 ;
>                 z:associate = "z" ;
>                 z:units = "-" ;
>                 z:long_name = "Level Index (increasing below surface)" ;
>         int time(time) ;
>                 time:units = "timesteps since 2006-01-01 00:00:00" ;
>                 time:title = "Time steps" ;
>                 time:tstep_sec = 86400.f ;
>                 time:long_name = "Time step axis" ;
>                 time:time_origin = " 2006-JAN-01 00:00:00" ;
>         float Evap(time, lat, lon) ;
>                 Evap:associate = "time lat lon" ;
>                 Evap:units = "kg m-2 day-1" ;
>                 Evap:long_name = "Total Evapotranspiration" ;
>                 Evap:missing_value = 1.e+20f ;
>
> // global attributes:
>                 :Conventions = "COARDS" ;
>                 :filename = "ISBA_Evap_exp2_2006.nc" ;
>                 :CreatedBy = "Aaron Boone at CNRM Meteo-France" ;
>                 :title = "ISBA results for ALMIP" ;
>                 :project = "ALMIP-PhaseI" ;
>                 :production = "Transfered to the single file on 20071120
> at 155716.264" ;
> }
>
> ddf file
>
> dset ISBA_EVAP_exp2_2006.nc
> dtype netcdf
> undef -1e15 missing_value
> unpack scale_factor add_offset
> title evaporation daily cumul
> xdef 101 linear  -20.  0.5
> ydef 51 linear  -5  0.5
> zdef 3 linear 1 1
> tdef 365 linear 00z01jan2006 1dy
> vars 1
> evap 1 t,x,y evaporation cumul
> endvars
>
> ------------------------------
> End of GRADSUSR Digest - 19 Nov 2007 to 20 Nov 2007 (#2007-272)
> ***************************************************************