Re: [idvusers] How do you time step 3-hourly NARR data in the IDV?

Hi Mike-

I can reproduce your problem with the NARR-A files and think it's a problem caused by there being multiple time dimensions in the NARR-A files since I had a similar problem with another dataset. If you load in a single file, you'll see that there are two times - the analysis time and a 6 hour forecast time. The latter is probably from the precip grids which are an accumulation from the initial time.

I suggest sending a note to support-idv@xxxxxxxxxxxxxxxx and they can work with the netCDF-Java developers on a solution.

I was going to say that the only (painful) workaround would be to load in each grid individually and then use the Grids->Time Steps->Merge time sequences Formula and select the individual grids from each file when the Field Selector comes up. You would select the parameter and then the analysis time (and level), then click Add selected, and then select the same from the next file. When you've selected them all, then click OK.

However, due to a recent change, this throws an error. I'll submit a ticket on that problem.

Don

On 1/3/12 10:25 AM, Mike Umscheid wrote:
Oh wow, I never even considered that drop down box in the Chooser!  That's
exactly what I am looking for.  I am able to aggregate successfully using
the narr-b files like you said... however, the narr-a files which have the
3D fields, are not being parsed correctly or something.  After loading the
aggregated grids and doing a right-click Properties>>  Times, I see all the
aggregated times, but when you go and select any of the fields (either 2D
or 3D), the Times tab only displays one default time instead of the total
number of aggregated times.  I wonder if this is a software bug??  Try
doing the same thing for the narr-a files and see if you can duplicate
this...

Mike U

On Tue, Jan 3, 2012 at 10:58 AM, Tom Whittaker<whittaker@xxxxxxxx>  wrote:

Mike --

Thanks for the link.  Try this:

In the Chooser, select the individual .grb files (CTRL+click) and then
set the "Data source type" as "Aggregate grids by time"....that worked
nicely for me (I assuming that the data sets you want are the ones
under the dates, with names like:  "narr-b 221 20111229 2100
000.grb")...

tom

On Tue, Jan 3, 2012 at 10:43 AM, Mike Umscheid<mike.umscheid@xxxxxxxx>
wrote:
Thanks for the reply Tom,

I am not having any luck with 2 or 3... but it does sound like I need to
investigate option 1 as I am not all that familiar with NCML in combining
datasets.  The NARR data I have been using is straight from the NARR
catalog
through the IDV
(http://nomads.ncdc.noaa.gov/thredds/catalog/narr/catalog.xml).  So I
guess
what I would need to do then is save the individual hourly dataset as a
local grid (*.nc) and then use one of the available tools (I see
something
called ToolsUI?) to merge the files into one netCDF?

Mike U


On Tue, Jan 3, 2012 at 9:50 AM, Tom Whittaker<whittaker@xxxxxxxx>
wrote:

Hi Mike...

The display rule is that if the data object has only one time, then it
is displayed along with all other "time steps"; hence, since both 18z
and 21z data have just one "time", they are displayed together.

I'm not familiar with the NARR data or how you are loading it, but
there are a couple of ways to make individual time period data be
combined:

1. using NCML to logically combine times
2. using the Chooser and picking more than one time/file using
SHIFT+click or CTRL+click
3. using the Formula under "Miscellaneous ->  Make a time sequence from
single time grids"

Hope this helps.

tom

On Tue, Jan 3, 2012 at 9:13 AM, Mike Umscheid<mike.umscheid@xxxxxxxx>
wrote:
IDV Users,

I'm not sure how many of you interrogate NARR datasets on the IDV, but
I'm
doing more of it now through the IDV using bundles and ISL scripts.
  One
big limitation I am finding is that I cannot time step/animate through
more
than one data file on the Map View pane.  For instance, if you load in
fields from an 18z file and then also a 21z file, the IDV just
displays
the
21z data right on top of the 18z data.  How do you configure the IDV
such
that for these hourly dataset files you can create animations and step
back
and forth through various times?  Any help/guidance is appreciated!
  Thanks,

Mike U
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--
Tom Whittaker
University of Wisconsin-Madison
Space Science&  Engineering Center (SSEC)
Cooperative Institute for Meteorological Satellite Studies (CIMSS)
1225 W. Dayton Street
Madison, WI  53706  USA
ph: +1 608 262 2759





--
Tom Whittaker
University of Wisconsin-Madison
Space Science&  Engineering Center (SSEC)
Cooperative Institute for Meteorological Satellite Studies (CIMSS)
1225 W. Dayton Street
Madison, WI  53706  USA
ph: +1 608 262 2759

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--
Don Murray
NOAA/ESRL/PSD and CIRES
303-497-3596
http://www.esrl.noaa.gov/psd/people/don.murray/