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[IDV #XYH-126534]: multiple file display

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  • Subject: [IDV #XYH-126534]: multiple file display
  • Date: Fri, 11 Apr 2008 09:41:40 -0600
Hi Randy-

> here is my wrf.nmcl file:
> 
> <?xml version="1.0" encoding="UTF-8"?>
> <netcdf
> xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
> 
> <aggregation dimName="Time" type="joinExisting">
> <netcdf
> location="wrfout_d01_2008-04-10_12:00:00"/>
> <netcdf
> location="wrfout_d01_2008-04-10_13:00:00"/>
> <netcdf
> location="wrfout_d01_2008-04-10_14:00:00"/>
> </aggregation>
> 
> </netcdf>
> 
> i get an error when opening the file:
> There was an error loading the data:
> Error creating data source:netcdf.grid with:
> /users/sleet/wrf_output/tmp/wrf.ncml
> unable to open grid:
> /users/sleet/wrf_output/tmp/wrf.ncml
> 
> am i doing something wrong.

Is this file in the same directory as the wrfout files?
Can you send me a sample file?

Don

> > Hi-
> >
> > > I have 24 netcdf files containing each hour of WRF
> > > output. I have no problem loading the datasets
> > into
> > > IDV, however, I want to display a single variable
> > > (e.g., 2 meter temperature) for all hours w/o
> > loading
> > > each hour manually. Is there a convenient way to
> > do
> > > this?
> >
> > Right now, we don't have an easy way to aggregate
> > the
> > separate files on the fly.  For GRIB products, there
> > is
> > a Data Source Type that will aggregate the
> > individual
> > timesteps into a single data source.  However, this
> > does
> > not work for the netCDF files because the time
> > dimension
> > has a different name.
> >
> > So, one option would be to write an NcML file that
> > would
> > aggregate the individual files into one dataset.
> > You
> > would then open that file.  The problem would be
> > that you
> > would need a different NcML file for each different
> > set
> > of files.  The NcML file would look like:
> >
> > <?xml version="1.0" encoding="UTF-8"?>
> > <netcdf
> >
> xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
> >
> >   <aggregation dimName="Time" type="joinExisting">
> >       <netcdf location="wrfout-d01-2006070100"/>
> >       <netcdf location="wrfout-d01-2006070103"/>
> >   </aggregation>
> >
> >
> > </netcdf>
> >
> > (also attached).  you could add as many:
> >
> >       <netcdf location=""/>
> >
> > lines as you have files.  Depending how you store
> > the data,
> > you might be able to use the scan feature like:
> >
> >     <scan location="/data/model/" suffix=".nc" />
> >
> > See the documentation on NcML for the scan options:
> >
> >
> http://www.unidata.ucar.edu/software/netcdf/ncml/v2.2/Aggregation.html
> >
> > Alternatively, if you are using IDV 2.4 or higher,
> > you can use the
> > Formula "Miscellaneous->Make a time sequence from
> > single time grids/images"
> > which would allow you to select each individual
> > timestep and
> > create a loop.  That can be tedious for many
> > timesteps and the
> > NcML approach would be easier at this point.
> >
> > Don Murray
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: XYH-126534
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> 
> 
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Ticket Details
===================
Ticket ID: XYH-126534
Department: Support IDV
Priority: Normal
Status: Open