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Re: Few questions...



Rob Weingruber wrote:

   Hi John -

Im back at it.....
Ok, so after perusing GridDatatype andGridCoordSystem, I have a few questions:
1. Can you explain the ensemble to me? Is that for climatologies? (if so, i understand 
the ensemble ;-).


models are sometimes run several (many) times with slight variations of the input, these are called 
"ensemble" runs. The set of results then show the fuuture in a more statistically 
meaningful way. these results could be represented as an extra "ensemble" dimension.

we havent yet tested this with any real world examples yet.
2. Is the RunTime the same as what I termed the 'generate time'? If so, might be better to use 'gen time' rather than run time, since a model run may have a gen time of 12Z, but it happens to be running at 12:18Z (my $0.02 ;-). 

im not sure, i could also imagine the argument "a model run may have a runtime of 
12Z, but it happens to be generated at 12:18Z".
maybe we can have a bakeoff, i've also heard "analysis time". 

Related to NCML:

3. Can I use the 'Forecast Model Run' yet?  If so, whudoIdo?


we are just finishing the "Forecast Model Run Collection" (fmrc) aggregation, you can try 
it out if you want, but i havent written docs yet.  (there was an older "Forecast Model 
Run" aggregation which is now deprecated.)

lets pick a simple dataset you want to do, and try serving it through the TDS:

 1. have a look at the motherlode test server models 
(http://motherlode.ucar.edu:9080/thredds/idd/models.html)
 2. install latest 3.13 development version of thredds.war (from 
http://www.unidata.ucar.edu/downloads/thredds/index.jsp)
 3. pick a simple dataset, i will show you what the catalog should be.
 4. ill try to get some docs written.

now that ive said all this, maybe you just want to access the fmrc aggregation 
dataset from java code?
4. How can I aggregate with the 2D time coordinate? I looked at the joinExisting 
doc http://www.unidata.ucar.edu/software/netcdf/ncml/v2.2/Aggregation.html,
and I still dunno what to do....


its likely you need the fmrc aggregation.



;-)  Thanks John!


yer welcome!
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