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Re: NullPointerException during aggregation

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  • Subject: Re: NullPointerException during aggregation
  • Date: Fri, 03 Nov 2006 10:23:49 -0700
Hi Jon:

Can you check if you get the same error in the latest 2.2.17 release?
I have fixed some bugs in aggregation, but im not sure if thats one of them.

thanks

Jon Blower wrote:

Hi all,

I'm having problems working with NcML aggregations and the 2.2.16
version of the Java NetCDF libraries.  I would like to aggregate
files:

NATL_1_28082006.nc
NATL_1_29082006.nc
NATL_1_30082006.nc
...

along the time dimension.  I tried an NcML file like this:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
  <aggregation dimName="time" type="joinNew">
    <variableAgg name="temperature"/>
    <variableAgg name="salinity"/>
    <scan location="/path/to/files/" suffix=".nc"
dateFormatMark="NATL_1_#ddMMyyyy" />
  </aggregation>
</netcdf>

This gave me a NullPointerException:

java.lang.NullPointerException
    java.util.Calendar.setTime(Calendar.java:1032)
    java.text.SimpleDateFormat.format(SimpleDateFormat.java:785)
    java.text.SimpleDateFormat.format(SimpleDateFormat.java:778)
    java.text.DateFormat.format(DateFormat.java:314)
ucar.nc2.units.DateFormatter.toDateTimeStringISO(DateFormatter.java:184) 
    ucar.nc2.ncml.Aggregation.crawlDirectory(Aggregation.java:817)

I think I know why this is.  There are other files in the same
directory of the form "NATL_120_28082006.nc" and I think the
aggregator is trying to match these.  Can I arrange it so that only
files that match the pattern "NATL_1_#ddMMyyyy.nc" are aggregated, and
all others are simply ignored?

I am reluctant to change the directory structure of my data because
other applications may depend on it.

Thanks in advance,
Jon



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