Re: [thredds] Scan Aggregation vs. Feature Collection

Please let me know also how it works, and if you get a working the XML for a 
sample datasst.

Thanks,

-Roy
On Oct 26, 2012, at 4:48 PM, John Caron wrote:

> Hi Kyle:
> 
> For GRID data aggregations, If they are GRIB format, use Feature Collection, 
> type=GRIB. Otherwise use type=FMRC, even if theres only one runtime. Let us 
> know any problems.
> 
> John
> 
> On 10/3/2012 10:09 AM, Kyle Wilcox wrote:
>> Hi John -
>> 
>> Just trying to clarify a few things when testing 4.3:
>> 
>> If we have a homogenous set of non-forecast GRID FeatureTypes (satellite), 
>> we should still use an 'old-style' NcML aggregation because there is no GRID 
>> FeatureCollection.
>> 
>> If we have a heterogeneous set of non-forecast GRID FeatureTypes (satellite 
>> passes on slightly different grids), there is currently no way to aggregate 
>> them in 4.3 because there is no GRID FeatureCollection.
>> 
>> Thanks ,
>> Kyle
>> 
>>> -----Original Message-----
>>> From: thredds-bounces@xxxxxxxxxxxxxxxx [mailto:thredds-
>>> bounces@xxxxxxxxxxxxxxxx] On Behalf Of John Caron
>>> Sent: Monday, July 23, 2012 5:50 PM
>>> To: Roy Mendelssohn
>>> Cc: thredds@xxxxxxxxxxxxxxxx
>>> Subject: Re: [thredds] Scan Aggregation vs. Feature Collection
>>> 
>>> Well, its complicated.
>>> 
>>> Old style aggregations, aka "NcML aggegations" remain supported. I think of
>>> these as low level index manipulations. These are embedded in NcML, either
>>> on the client or in TDS config catalog, see:
>>> 
>>> http://www.unidata.ucar.edu/projects/THREDDS/tech/tds4.3/tutorial/NcML.ht
>>> m
>>> 
>>> We can do much better when we know the "feature type", and the new way is
>>> called "feature collections":
>>> 
>>> 1) type=FMRC is for gridded data. Works mostly of in 4.2, but refactored in 
>>> 4.2
>>> and still testing.
>>> 2) type=GRIB is for GRIB data, which is a special kind of gridded data.
>>> This supersedes FMRC when the data is in GRIB. Only in 4.3, ready for beta
>>> test.
>>> 3) type=point are for point feature types. Still in alpha in 4.3
>>> 
>>> NcML works fins when you know what you are doing and you have
>>> homogenous files. feature collections are intededd to be easier to use and
>>> tolerate heterogeneous files.
>>> 
>>> John
>>> 
>>> 
>>> On 7/23/2012 3:27 PM, Roy Mendelssohn wrote:
>>>> But is this just for FMRC aggregation, or for all aggregations?  I could 
>>>> swear I
>>> remember a web age with feature collections that "grid" was a feature type,
>>> but when I looked the other day, it was point, station and grib I believe.
>>> Maybe it was my old age and bad vision seeing "grid" for "grib".  If there 
>>> is an
>>> aggregation for featureType=grid, can you point me to the page that 
>>> describes
>>> this.
>>>> 
>>>> We do not have any FMRC aggregations, but if there all of our aggregations
>>> should be feature collections, then I have a lot of editing to do on our xml
>>> files.
>>>> 
>>>> Thanks,
>>>> 
>>>> -Roy
>>>> 
>>>> On Jul 23, 2012, at 1:59 PM, John Caron wrote:
>>>> 
>>>>> On 7/19/2012 11:50 AM, Roy Mendelssohn wrote:
>>>>>> Hi All:
>>>>>> 
>>>>>> I have asked this before and am not certain that I ever got a response.
>>> For TDS 3.0 is it correct to assume that scan aggregation is deprecated and 
>>> we
>>> should be using feature collections for aggregation instead?
>>>>> Hi Roy:
>>>>> 
>>>>> Yes correct, though we are still debugging the FMRCs in 4.3.
>>>>> 
>>>>> For GRIB files, you really want to use feature collections , type = GRIB.
>>>>> 
>>>>> 4.3.12 is the last alpha, next release will be beta. It should be ready 
>>>>> this
>>> week.
>>>>> 
>>>>> Would appreciate use and feedback.
>>>>> 
>>>>> John
>>>>> 
>>>>> _______________________________________________
>>>>> thredds mailing list
>>>>> thredds@xxxxxxxxxxxxxxxx
>>>>> For list information or to unsubscribe,  visit:
>>>>> http://www.unidata.ucar.edu/mailing_lists/
>>>> **********************
>>>> "The contents of this message do not reflect any position of the U.S.
>>> Government or NOAA."
>>>> **********************
>>>> Roy Mendelssohn
>>>> Supervisory Operations Research Analyst NOAA/NMFS Environmental
>>>> Research Division Southwest Fisheries Science Center
>>>> 1352 Lighthouse Avenue
>>>> Pacific Grove, CA 93950-2097
>>>> 
>>>> e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
>>>> voice: (831)-648-9029
>>>> fax: (831)-648-8440
>>>> www: http://www.pfeg.noaa.gov/
>>>> 
>>>> "Old age and treachery will overcome youth and skill."
>>>> "From those who have been given much, much will be expected"
>>>> "the arc of the moral universe is long, but it bends toward justice" -MLK 
>>>> Jr.
>>> 
>>> _______________________________________________
>>> thredds mailing list
>>> thredds@xxxxxxxxxxxxxxxx
>>> For list information or to unsubscribe,  visit:
>>> http://www.unidata.ucar.edu/mailing_lists/

**********************
"The contents of this message do not reflect any position of the U.S. 
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097

e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/

"Old age and treachery will overcome youth and skill."
"From those who have been given much, much will be expected" 
"the arc of the moral universe is long, but it bends toward justice" -MLK Jr.



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