Re: [thredds] Using the NC4 String type for a variable containing a "cf_role" attribute

• To: John Caron <caron@xxxxxxxxxxxxxxxx>
• Subject: Re: [thredds] Using the NC4 String type for a variable containing a "cf_role" attribute
• From: "Signell, Richard" <rsignell@xxxxxxxx>
• Date: Mon, 16 Dec 2013 10:53:14 -0500

John,

Even though you will modify NJ to handle this, you are saying: If producers
want to deliver CF-compliant data, they should be not be writing string
variables.

Right?

Thanks,
Rich


On Mon, Dec 16, 2013 at 9:52 AM, John Caron <caron@xxxxxxxxxxxxxxxx> wrote:

>  On 12/12/2013 1:27 PM, Kyle Wilcox wrote:
>
> I have two files where the only difference is the variable type of the
> "feature_type_instance" variable.
>
> When using a Char array, it works just fine.
> When using a String, NCJ fails to find a StructureRecord:
>
> java.lang.IllegalStateException: Cant find Structure record
> Â  Â  at
> ucar.nc2.ft.point.standard.Table$TableStructure.<init>(Table.java:253)
> Â  Â  at ucar.nc2.ft.point.standard.Table.factory(Table.java:110)
> Â  Â  at ucar.nc2.ft.point.standard.NestedTable.<init>(NestedTable.java:98)
> Â  Â  at
> ucar.nc2.ft.point.standard.TableAnalyzer.analyze(TableAnalyzer.java:406)
> Â  Â  at
> ucar.nc2.ft.point.standard.TableAnalyzer.factory(TableAnalyzer.java:294)
> Â  Â  at
> ucar.nc2.ft.point.standard.PointDatasetStandardFactory.isMine(PointDatasetStandardFactory.java:114)
> Â  Â  at
> ucar.nc2.ft.FeatureDatasetFactoryManager.wrap(FeatureDatasetFactoryManager.java:272)
> Â  Â  at
> ucar.nc2.ft.FeatureDatasetFactoryManager.open(FeatureDatasetFactoryManager.java:243)
>
>
> You can try loading each file into the FeatureTypes/PointFeature tab to
> see the stacktrace from the String file (I've attached them).
>
> Based on CF docs (
> http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/cf-conventions.html#coordinates-metadata)
> it states:
> "The variable carrying the cf_role attribute may have any data type."
>
>
> Is this a bug in NCJ?
>
> Thanks,
> Kyle
>
>
> _______________________________________________
> thredds mailing listthredds@xxxxxxxxxxxxxxxx
> For list information or to unsubscribe,  visit: 
> http://www.unidata.ucar.edu/mailing_lists/
>
>
> Hi Kyle:
>
> CF only deals with classic netcdf data model, which doesnt have Strings.
> However, the CDM deals with the extended model wherever possible, so yes, i
> think this is a bug and we'll get it fixed.
>
> John
>
> _______________________________________________
> thredds mailing list
> thredds@xxxxxxxxxxxxxxxx
> For list information or to unsubscribe,  visit:
> http://www.unidata.ucar.edu/mailing_lists/
>



-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598

• Follow-Ups:
  • Re: [thredds] Using the NC4 String type for a variable containing a "cf_role" attribute
    • From: John Caron

• References:
  • [thredds] Using the NC4 String type for a variable containing a "cf_role" attribute
    • From: Kyle Wilcox
  • Re: [thredds] Using the NC4 String type for a variable containing a "cf_role" attribute
    • From: John Caron