[thredds] NcML Aggregation errors

• To: <thredds@xxxxxxxxxxxxxxxx>
• Subject: [thredds] NcML Aggregation errors
• From: "Comiskey, Glenn" <g.comiskey@xxxxxxxx>
• Date: Tue, 10 Jan 2012 14:16:10 -0000

Hi,
 
Dataset info (16495 files):
 dimensions:
   time = 1;
   time1 = 1;
   .
   .
 variables:
   float Potential_temperature(time=1, sigma=1, lat=181, lon=360);
   float Pressure_vertical_velocity(time=1, isobaric3=21, lat=181,
lon=360);
   float Max_temperature(time1=1, height_above_ground1=1, lat=181,
lon=360);
   float Min_temperature(time1=1, height_above_ground1=1, lat=181,
lon=360);
 
Note: There are numerous other dimesions and variables declared in the
dataset.
 
1.    NcML aggregation statement:
<aggregation dimName="time1" type="joinExisting">
<scan location="//fgwfnas1/data/fnl/grib1/" subdirs="true"
suffix=".grib"/>
</aggregation>
 
Can anyone explain what the following error means:
2012-01-10T13:51:19.264 +0000 [     38525][      17] ERROR -
thredds.server.opendap.OpendapServlet - path=
/joinExisting1/joinExisting1.nc.html
java.lang.NullPointerException
 at
ucar.nc2.ncml.AggregationOuterDimension$CacheVar.read(AggregationOuterDi
mension.java:913)
  
2.    NcML aggregation statement:
<aggregation dimName="time" type="joinExisting">
<scan location="//fgwfnas1/data/fnl/grib1/" subdirs="true"
suffix=".grib"/>
</aggregation>
 .
Can anyone explain why the following aggregates variable is declared in
the DDS:
Dataset {
    Grid {
     ARRAY:
        Float32 Potential_temperature[time1 = 1][sigma = 1][lat =
181][lon = 360];
     MAPS:
        Int32 time1[time1 = 1];
        Float64 sigma[sigma = 1];
        Float64 lat[lat = 181];
        Float64 lon[lon = 360];
    } Potential_temperature;
    Grid {
     ARRAY:
        Float32 Pressure_vertical_velocity[time1 = 1][isobaric4 =
21][lat = 181][lon = 360];
     MAPS:
        Int32 time1[time1 = 1];
        Float64 isobaric4[isobaric4 = 21];
        Float64 lat[lat = 181];
        Float64 lon[lon = 360];
    } Pressure_vertical_velocity;
 
Kind regards,
 
Glenn Comiskey
Data System Administrator