Re: [netcdfgroup] Using IDL to generate NetCDF 4 files

• To: Mark Rivers <rivers@xxxxxxxxxxxxxxxxx>
• Subject: Re: [netcdfgroup] Using IDL to generate NetCDF 4 files
• From: Ajay Krishnan - NOAA Affiliate <ajay.krishnan@xxxxxxxx>
• Date: Wed, 13 May 2015 20:38:45 -0400

Mark,

Perfect! That seemed to do the trick. Thank you so much!

Regards,
Ajay

On Wed, May 13, 2015 at 4:23 PM, Mark Rivers <rivers@xxxxxxxxxxxxxxxxx>
wrote:

>  I have only used IDL to create netCDF3 files, not netCDF4 files.
> However, I suspect that the code needs to be changed similar to the
> following:
>
>
>
> From
>
>
>
>       ncdf_attput, lat_id, 'standard_name’, ‘latitude’
>
>
>
> to
>
>
>
>       ncdf_attput, lat_id, 'standard_name’, ‘latitude’, /char
>
>
>
> The /char means to store the data as a byte array, rather than a string.
> It is possible that the existing code is explicitly using the /string
> keyword, which would need to be replaced with /char.
>
>
>
> Mark
>
>
>
>
>
> *From:* netcdfgroup-bounces@xxxxxxxxxxxxxxxx [mailto:
> netcdfgroup-bounces@xxxxxxxxxxxxxxxx] *On Behalf Of *Ajay Krishnan - NOAA
> Affiliate
> *Sent:* Wednesday, May 13, 2015 3:02 PM
> *To:* netcdfgroup@xxxxxxxxxxxxxxxx
> *Subject:* [netcdfgroup] Using IDL to generate NetCDF 4 files
>
>
>
> Hi everyone,
>
>
>
> One of the data producers that I am working with is using IDL to generate
> NetCDF-4 files.
>
>
>
> I am not sure about the code that he is using to generate these files but
> I am unable to read them in THREDDS.
>
>
>
> An ncdump of the file looks like this:
>
>
>
> netcdf baa_b05kmnn_20150101 {
>
> dimensions:
>
>         time = 1 ;
>
>         lat = 3600 ;
>
>         lon = 7200 ;
>
> variables:
>
>         int time(time) ;
>
>                 string time:long_name = "reference time of sst field" ;
>
>                 string time:standard_name = "time" ;
>
>                 string time:axis = "T" ;
>
>                 string time:calendar = "Gregorian" ;
>
>                 string time:units = "seconds since 1981-01-01 00:00:00" ;
>
>                 string time:comment = "Nominal time of Level 4 analysis" ;
>
>                 string time:coverage_content_type = "coordinate" ;
>
>         float lat(lat) ;
>
>                 string lat:long_name = "latitude" ;
>
>                 string lat:standard_name = "latitude" ;
>
>                 string lat:units = "degrees_north" ;
>
>                 string lat:axis = "Y" ;
>
>                 lat:valid_min = -90.f ;
>
>                 lat:valid_max = 90.f ;
>
>                 string lat:comment = "equirectangular projection" ;
>
>                 string lat:coverage_content_type = "coordinate" ;
>
>                 string lat:grid_mapping = "crs" ;
>
>         float lon(lon) ;
>
>                 string lon:long_name = "longitude" ;
>
>                 string lon:standard_name = "longitude" ;
>
>                 string lon:units = "degrees_east" ;
>
>                 string lon:axis = "X" ;
>
>                 lon:valid_min = -180.f ;
>
>                 lon:valid_max = 180.f ;
>
>                 string lon:comment = "equirectangular projection" ;
>
>                 string lon:coverage_content_type = "coordinate" ;
>
>                 string lon:grid_mapping = "crs" ;
>
>         byte surface_flag(lat, lon) ;
>
>                 string surface_flag:long_name = "Pixel characteristics
> flag array" ;
>
>                 string surface_flag:units = "none" ;
>
>                 string surface_flag:coordinates = "lon lat" ;
>
>                 string surface_flag:comment = "An array in the same
> dimension as the data array classifies land, missing, and ice pixels that
> are all flaged by the same missing_value in the data array(s)." ;
>
>                 surface_flag:flag_values = 0s, 1s, 2s, 4s ;
>
>                 string surface_flag:flag_meanings =
> "valid-water,land,missing,ice" ;
>
>                 string surface_flag:coverage_content_type =
> "thematicClassification" ;
>
>                 string surface_flag:grid_mapping = "crs" ;
>
>
>
>
>
> I guess the issue is arriving from the prefix 'string' which probably
> crept in while generating the attributes. When I get rid of the 'string'
> and recreate the NetCDF file, it works absolutely fine.
>
>
>
> Since I don't have an idea as to how IDL works, can someone here guide me
> as to how this can be avoided while generating the netcdf file from IDL?
>
>
>
> This issue arises only when the data provided creates NetCDF 4 files. The
> NetCDF 3 files run just fine.
>
>
>
> Any help / documentation would be appreciated.
>
>
>
> Thanks,
>
> Ajay
>
>
>
>
>

• References:
  • [netcdfgroup] Using IDL to generate NetCDF 4 files
    • From: Ajay Krishnan - NOAA Affiliate
  • Re: [netcdfgroup] Using IDL to generate NetCDF 4 files
    • From: Mark Rivers