Hi Nathan,
The NetCDF-Java OPeNDAP client will successfully parse a "missing_value" of
"NaN", but not "nan". That's why you got that exception.
I'm not sure how you ran into the lower-case variant though. For example, I
see the following on
http://thredds.ucar.edu/thredds/dodsC/grib/NCEP/GFS/Global_0p25deg/Best.das
u-component_of_wind_isobaric {
String long_name "u-component of wind @ Isobaric surface";
String units "m/s";
String abbreviation "UGRD";
Float32 missing_value NaN;
String grid_mapping "LatLon_Projection";
String coordinates "reftime time isobaric lat lon ";
String Grib_Variable_Id "VAR_0-2-2_L100";
Int32 Grib2_Parameter 0, 2, 2;
String Grib2_Parameter_Category "Momentum";
String Grib2_Parameter_Name "u-component of wind";
String Grib2_Level_Type "Isobaric surface";
String Grib2_Generating_Process_Type "Forecast";
}
On Mon, Jun 20, 2016 at 12:11 PM, Nathan Potter <ndp@xxxxxxxxxxx> wrote:
>
>
> Rich,
>
>
> That’s different software using a different interface to access the data.
> While the TDS uses “ncWMS” as a library to provide WMS services for data it
> does not, as far as I know utilize:
>
> a) ncWMS2 which is the latest WMS software from the Reading Science Center
>
> b) The Java-NetCDF libraries ability to read DAP datasets as a mechanism
> for accessing data for it’s “captive” WMS.
>
>
> So that’s good that it works in TDS, but really my question is about
> Java-NetCDF failing to correctly identify/process missing_value attributes
> whose value is “nan”, which is the failure mode that ncWMS2 is experiencing.
>
> Interestingly, it doesn’t appear to be a problem when I direct ncWMS2 to
> directly access the netcdf subset file. It’s only a problem when ncWMS2 is
> accessing the dataset via DAP2 (which is done through the Java-NetCDF
> library)
>
> I;ve cc’d Unidata support TDS-users. Maybe someone there has had this
> experience or knows a work around.
>
> Thanks for the help Rich!
>
> Nathan
>
>
>
>
> > On Jun 20, 2016, at 10:31 AM, Signell, Richard <rsignell@xxxxxxxx>
> wrote:
> >
> > This WMS request seems to work okay:
> >
> http://thredds.ucar.edu/thredds/wms/grib/NCEP/GFS/Global_0p25deg/Best?LAYERS=u-component_of_wind_isobaric&ELEVATION=100&TIME=2016-06-20T00%3A00%3A00.000Z&TRANSPARENT=true&STYLES=boxfill%2Frainbow&COLORSCALERANGE=-52.3%2C160&NUMCOLORBANDS=20&LOGSCALE=false&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&FORMAT=image%2Fpng&SRS=EPSG%3A4326&BBOX=-180,-90,180,90&WIDTH=256&HEIGHT=256
> >
> > On Mon, Jun 20, 2016 at 12:34 PM, Nathan Potter <ndp@xxxxxxxxxxx> wrote:
> >> I got that datset-subset but I can’t get ncWMS to load it because:
> >>
> >> 2016-06-20 09:22:03 ERROR NetcdfDataset:1043 - Error
> openDodsByReflection:
> >> java.lang.IllegalArgumentException: Illegal Numeric Value for Attribute
> >> Value for missing_value
> >> at ucar.nc2.dods.DODSAttribute.<init>(DODSAttribute.java:114)
> >> at ucar.nc2.dods.DodsV.addAttribute(DodsV.java:441)
> >> at ucar.nc2.dods.DodsV.addAttributeTable(DodsV.java:432)
> >> at ucar.nc2.dods.DodsV.parseDAS(DodsV.java:407)
> >> at ucar.nc2.dods.DODSNetcdfFile.<init>(DODSNetcdfFile.java:296)
> >> at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
> >> at
> >>
> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
> >> at
> >>
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
> >> at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
> >> at
> >>
> ucar.nc2.dataset.NetcdfDataset.openDodsByReflection(NetcdfDataset.java:1040)
> >>
> >> Which looks like a bug down inside Java-NetCDF.
> >>
> >> At least to me it looks like a bug, from the DAS:
> >>
> >> u-component_of_wind_isobaric {
> >> String long_name "u-component of wind @ Isobaric surface";
> >> String units "m/s";
> >> String abbreviation "UGRD";
> >> Float32 missing_value nan;
> >> String grid_mapping "LatLon_Projection";
> >> String coordinates "reftime time isobaric lat lon lat lon";
> >> String Grib_Variable_Id "VAR_0-2-2_L100";
> >> Int32 Grib2_Parameter 0, 2, 2;
> >> String Grib2_Parameter_Category "Momentum";
> >> String Grib2_Parameter_Name "u-component of wind";
> >> String Grib2_Level_Type "Isobaric surface";
> >> String Grib2_Generating_Process_Type "Forecast";
> >> }
> >>
> >>
> >>
> >> Do you know if this is a common problem with an easy workaround, or
> should I
> >> badger Unidata with a bug report?
> >>
> >> N
> >>
> >>
> >>
> >> On Jun 17, 2016, at 9:16 AM, Nathan Potter <ndp@xxxxxxxxxxx> wrote:
> >>
> >> Rich,
> >>
> >> Yeah, I do want all that. We are working on WCS for 3D+time (4
> independent
> >> vars) and I was working to get some real test datasets.
> >>
> >>
> >> N
> >>
> >>
> >> On Jun 17, 2016, at 7:41 AM, Signell, Richard <rsignell@xxxxxxxx>
> wrote:
> >>
> >> Nathan,
> >> I took your same request, but changed the horizontal stride from 1 to
> >> 100 (horizStride=100)
> >>
> >>
> http://thredds.ucar.edu/thredds/ncss/grib/NCEP/GFS/Global_0p25deg/best?var=u-component_of_wind_isobaric&var=v-component_of_wind_isobaric&horizStride=100&time_start=2016-06-13T00%3A00%3A00Z&time_end=2016-07-02T06%3A00%3A00Z&timeStride=1&vertCoord=&addLatLon=true&accept=netcdf4
> >>
> >> It took 12 minutes, but successfully completed the request, delivering
> >> a 2MB netcdf4 file which I've attached and placed here:
> >>
> >>
> http://geoport-dev.whoi.edu/thredds/catalog/usgs/data2/rsignell/test/catalog.html?dataset=usgs/data2/rsignell/test/best.nc
> >>
> >> Checking out the DDS at
> >>
> http://geoport-dev.whoi.edu/thredds/dodsC/usgs/data2/rsignell/test/best.nc.dds
> >> I see that you are asking for 117 time steps, and there are 31
> >> vertical levels in these variables.
> >>
> >> Did you really want all that?
> >>
> >> Your original request (with horizStride=1) would have been a request
> >> for 100x100=10,000 times more data, or roughly 20GB of data. Perhaps
> >> that's why it crapped out?
> >>
> >> But I agree the original error message you received was not very
> >> informative.
> >>
> >> -Rich
> >>
> >>
> >>
> >> On Thu, Jun 16, 2016 at 1:18 PM, Nathan Potter <ndp@xxxxxxxxxxx> wrote:
> >>
> >>
> >> I used this form:
> >>
> >>
> http://thredds.ucar.edu/thredds/ncss/grib/NCEP/GFS/Global_0p25deg/best/dataset.html
> >>
> >> To construct this NetCDF Subset Service request:
> >>
> >>
> http://thredds.ucar.edu/thredds/ncss/grib/NCEP/GFS/Global_0p25deg/best?var=u-component_of_wind_isobaric&var=v-component_of_wind_isobaric&horizStride=1&time_start=2016-06-13T00%3A00%3A00Z&time_end=2016-07-02T06%3A00%3A00Z&timeStride=1&vertCoord=&addLatLon=true&accept=netcdf4
> >>
> >> Which returns the following remarkably cryptic message:
> >>
> >> first (-66) must be >= 0
> >>
> >> Does anybody have some thoughts as to what I might change to make the
> >> request successful, or to get a more understandable message?
> >>
> >>
> >> Thanks,
> >>
> >> Nathan
> >>
> >>
> >> = = =
> >> Nathan Potter ndp at opendap.org
> >> OPeNDAP, Inc. +1.541.231.3317
> >>
> >> _______________________________________________
> >> NOTE: All exchanges posted to Unidata maintained email lists are
> >> recorded in the Unidata inquiry tracking system and made publicly
> >> available through the web. Users who post to any of the lists we
> >> maintain are reminded to remove any personal information that they
> >> do not want to be made public.
> >>
> >>
> >> 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
> >> <best.nc4>
> >>
> >>
> >> = = =
> >> Nathan Potter ndp at opendap.org
> >> OPeNDAP, Inc. +1.541.231.3317
> >>
> >>
> >> = = =
> >> Nathan Potter ndp at opendap.org
> >> OPeNDAP, Inc. +1.541.231.3317
> >>
> >
> >
> >
> > --
> > Dr. Richard P. Signell (508) 457-2229
> > USGS, 384 Woods Hole Rd.
> > Woods Hole, MA 02543-1598
>
> = = =
> Nathan Potter ndp at opendap.org
> OPeNDAP, Inc. +1.541.231.3317
>
> _______________________________________________
> NOTE: All exchanges posted to Unidata maintained email lists are
> recorded in the Unidata inquiry tracking system and made publicly
> available through the web. Users who post to any of the lists we
> maintain are reminded to remove any personal information that they
> do not want to be made public.
>
>
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