NetCDF Xdfopen problem

[Mike Johnson]

Donata - thanks for response.  I tried your suggestion and it generated the
following, do you have any idea why?  thanks.
1.  ddf file now looks like:

DSET  ^20070824_1200.nc
TITLE Example NetCDF File
UNDEF -99999.
XDEF x 200 LINEAR -125.117 2.5
YDEF y 200 LINEAR 40.2711 2.5
ZDEF levels_1 1 LINEAR 1 1
TDEF n_valtimes 39 LINEAR 12Z24AUG2007 1HR
VARS 2
ws=>ws 1 0 t,z,y,x Wind Speed
wd=>wd 1 0 t,z,y,x Wind Direction
ENDVARS

2.  Error now looks like:
xdfopen 20070824_1200.ddf
Scanning Description File: 20070824_1200.ddf
XDFopen Error:  Missing DSET record.
The data file was not opened.

I'm not understanding this error at all...Do you have any idea?

thanks

Mike Johnson
Senior Forecaster,
Medford OR Weather Forecast Office
National Weather Service, NOAA
(541) 776-4344



Donata Giglio wrote:
> Hi!
> I would try to change these lines:
>
> ZDEF levels_1 1 LINEAR 1 1
> ws=>ws 1 0 t,z,y,x Wind Speed
> wd=>wd 1 0 t,z,y,x Wind Direction
>
> I hope this helps :-)
> Bye,
> Donata
>
> --- Mike Johnson <Mike.W.Johnson at NOAA.GOV> ha scritto:
>
>
>> I've just recently returned to the GRADS community
>> from an extended
>> absence and was hoping someone could give some
>> advice on reading a
>> netcdf file (of which I have no previous
>> experience).  Anyway, I've
>> tried a number of things relative to online
>> documentation and examples
>> from the users group.  So far I've been unsuccessful
>> in opening the
>> file. I am using GrADS v1.9b4.  thanks in advance...
>>
>> Mike Johnson
>>
>> Here's symptoms of what I thought was the most
>> promising methodology.
>>
>> *1.  I created a data descriptor file
>> "20070824_1200.ddf" with following:*
>>
>> DSET  ^20070824_1200.nc
>> TITLE Example NetCDF File
>> UNDEF -99999.
>> XDEF x 200 LINEAR -125.117 2.5
>> YDEF y 200 LINEAR 40.2711 2.5
>> ZDEF levels_1 LINEAR 1 1
>> TDEF n_valtimes 39 LINEAR 12Z24AUG2007 1HR
>> VARS 2
>> ws=>ws 1 t,z,y,x Wind Speed
>> wd=>wd 1 t,z,y,x Wind Direction
>> ENDVARS
>>
>> *2.  error produced:*
>> xdfopen 20070824_1200.ddf
>> Scanning Description File: 20070824_1200.ddf
>> XDFopen Error:  Missing or invalid dimension size.
>>  --> The invalid description file record is:
>>  --> zdef levels_1 linear 1 1
>>  The data file was not opened.
>>
>> *3.  partial ncdump output of 20070824_1200.nc:*
>>  netcdf 20070824_1200 {
>> dimensions:
>>              record = UNLIMITED ; // (39 currently)
>>              n_valtimes = 39 ;
>>              data_variables = 2 ;
>>              charsPerLevel = 11 ;
>>              namelen = 132 ;
>>              x = 200 ;
>>              y = 200 ;
>>              levels_1 = 1 ;
>> variables:
>>              float ws(record, levels_1, y, x)
>>                          ws:long_name = "Wind Speed"
>> ;
>>                          ws:units = "m/s" ;
>>                          ws:udunits = "meter/sec" ;
>>                          ws:uiname = "windSpeed" ;
>>                          ws:valid_range = -150.f,
>> 150.f ;
>>                          ws:_FillValue = -99999.f ;
>>                          ws:_n3d = 1 ;
>>                          ws:levels = "FHAG 10" ;
>>             char wsLevels(levels_1, charsPerLevel) ;
>>             char wsInventory(n_valtimes, levels_1) ;
>>             float wd(record, levels_1, y, x) ;
>>                          wd:long_name = "Wind
>> Direction" ;
>>                          wd:units = "degree_True" ;
>>                          wd:udunits = "degree_True"
>> ;
>>                          wd:uiname = "windDir" ;
>>                          wd:valid_range = 0.f, 360.f
>> ;
>>                          wd:_FillValue = -99999.f ;
>>                          wd:_n3d = 1 ;
>>                          wd:levels = "FHAG 10"
>>              char wdlevels(levels_1, charsPerLevel)
>> ;
>>              char wdInventory(n_valtimes, levels_1)
>> ;
>>              int valtimeMINUSreftime(n_valtimes) ;
>>                           valtimeMINUSreftime:units
>> = "seconds"
>>              double reftime ;
>>                           reftime:long_name =
>> "reference time" ;
>>                           reftime:units = "seconds
>> since (1970-1-1
>> 00:00:00:0)" ;
>>              char origin(namelen) ;
>>              char model(namelen) ;
>> // global attributes:
>>                           :projIndex = 3 ;
>>                           :projName = "LATLON"
>>                           :centralLat = 42.5392f ;
>>                           :centralLon = -122.1475f ;
>>                           :rotation = 25.f ;
>>                           :lat00 = 40.2711f ;
>>                           :lon00 = -125.117f ;
>>                           :latNxNy = 44.7219f ;
>>                           :lonNxNy = -118.9594f ;
>>                           :dxKm = 2.5f ;
>>                           :dyKm = 2.5f ;
>> data:
>>
>> ws =
>> 8., 8.6,...............................
>>
>>
>
>
>
>
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