Hi John,
My responses inline below.
Andrew
----- Original Message -----
From: "John Caron" <caron at unidata.ucar.edu>
To: <cf-metadata at cgd.ucar.edu>
Sent: Saturday, April 28, 2012 2:39 AM
Subject: Re: [CF-metadata] Ocean CTD data following CF Conventions v1.6
> Hi Andrew:
>
> You can use a dimension=1 instead of a scalar.
OK, you mean if one used the vector method.
>
> But you cant use
>
> lat(lat)
> lon(lon)
> time(time)
>
> the correct usage in the single profile case would be:
>
> lat(profile)
> lon(profile)
> time(profile)
So, do you mean in the vector method have this? (simpler I guess to have common
profile dimension = 1)
dimensions:
profile=1
pressure = 57
variables:
lat(profile)
lon(profile)
time(profile)
pressure(pressure)
temperature(pressure)
Instead of this?
Dimensions:
time=1
lat=1
lon=1
pressure=57
Variables:
time(time)
lat(lat)
lon(lon)
pressure(pressure)
temperature(pressure)
>
> John
>
> On 4/27/2012 12:03 AM, andrew walsh wrote:
>> Hi John,
>>
>> Thanks for your advice.
>> For a single vertical profile and single valued time, lat, long.
>> it seems there are two acceptable ways i.e 1 element vector or single valued
>> scalar.
>>
>> Quoting from 'section 2.4 Dimensions' of CF standard:
>>
>> 1 element vector:
>>
>> "Dimensions may be of any size, including unity. When a single value of some
>> coordinate applies to all the values in a variable, the recommended means of
>> attaching this information to the variable is by use of a dimension of size
>> unity with a one-element coordinate variable.
>>
>> and in the next sentence a scalar:
>>
>> "It is also acceptable to use a scalar coordinate variable which eliminates
>> the need for an associated size one dimension in the data variable."
>>
>> 1) ***Vector co-ordinate variables*******
>>
>> Dimensions:
>> time=1
>> pressure=56
>> lat=1
>> lon=1
>>
>> Variables:
>> time(time)
>> lat(lat)
>> lon(lon)
>> temperature(pressure)
>>
>> 2) **Scalar co-ordinate varaibles****
>>
>> Dimensions:
>>
>> pressure =56
>>
>> Variables:
>> time
>> lat
>> lon
>> temperature(pressure)
>>
>> The scalar approach you suggest as in section "H.3.3. Single profile" of the
>> CF v1.6 standard
>> is simpler than the vector approach so we will take your advice.
>>
>> Regards,
>>
>> Andrew
>>
>>
>> ----- Original Message ----- From: "John Caron" <caron at unidata.ucar.edu>
>> To: "andrew walsh" <awalsh at metoc.gov.au>
>> Cc: <cf-metadata at cgd.ucar.edu>; "Luke Callcut" <luke at metoc.gov.au>;
>> <greg at metoc.gov.au>
>> Sent: Thursday, April 26, 2012 10:48 AM
>> Subject: Re: [CF-metadata] Ocean CTD data following CF Conventions v1.6
>>
>>
>>> Hi andrew:
>>>
>>> The file you sent (20110818T001140Z_M_HI504BEN.nc) appears to be a single
>>> profile. Assuming that, you would use the following template:
>>>
>>> http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/cf-conventions.html#idp8363696
>>>
>>> note that lat, lon and time coordinates all have to be scalars.
>>>
>>> John
>>>
>>> On 4/18/2012 8:24 PM, andrew walsh wrote:
>>>> Hi John,
>>>>
>>>> We have now constructed a real netCDF file for you to check. QC flag
>>>> variables have been added in. The QC flagging method is based on the
>>>> proposed IODE scheme in (1) below.
>>>>
>>>> Attached are the sample .nc file, text (ncdump) of same and a document
>>>> specifying the CDL.
>>>>
>>>> Thanks and Regards,
>>>>
>>>> Andrew Walsh
>>>>
>>>>
>>>> Ref.
>>>>
>>>> (1) Konovalov et. al (March 2012), Proposal to adopt a quality flag scheme
>>>> standard
>>>> for oceanographic and marine meteorological data, Version 1.2.
>>>>
>>>> ----- Original Message ----- From: "John Caron" <caron at unidata.ucar.edu>
>>>> To: "andrew walsh" <awalsh at metoc.gov.au>
>>>> Sent: Thursday, April 05, 2012 10:44 AM
>>>> Subject: Re: [CF-metadata] Ocean CTD data following CF Conventions v1.6
>>>>
>>>>
>>>>> ok
>>>>>
>>>>> On 4/4/2012 6:42 PM, andrew walsh wrote:
>>>>>> Hi John,
>>>>>>
>>>>>> Thank for your offer to check a sample netCDF CTD data file. At moment we
>>>>>> don't have
>>>>>> some real .nc file but when we do I can send you a file for checking.
>>>>>>
>>>>>> Andrew
>>>>>>
>>>>>> ----- Original Message ----- From: John Caron
>>>>>> To: cf-metadata at cgd.ucar.edu
>>>>>> Sent: Wednesday, April 04, 2012 5:55 AM
>>>>>> Subject: Re: [CF-metadata] Ocean CTD data following CF Conventions v1.6
>>>>>>
>>>>>>
>>>>>> Hi all:
>>>>>>
>>>>>> Lets see, I havent followed the entire conversation, but:
>>>>>>
>>>>>> 1) Andrew if you can send me a sample file (not just the CDL) I can check
>>>>>> if it works in the CDM with the new 1.6 conventions, and maybe give you
>>>>>> some advice from my POV.
>>>>>>
>>>>>> 2) Aggregation in the CDM comes in 2 flavors. 1) The original
>>>>>> implementation simply appends multidimensional arrays together, eg
>>>>>> "joinNew " and "joinExisting" NCML aggregation. I call it "syntactic
>>>>>> aggregation" because it doesnt know what its aggregating, and the
>>>>>> homogeneity requirements are strict. 2) "Feature Type collections" (aka
>>>>>> "semantic aggregation") are the more recent development. These understand
>>>>>> the coordinate information of the data, and so can handle variations in
>>>>>> the representation, eg ragged arrays, scalar coordinates, etc. In this
>>>>>> case, the CDM understands a dataset as a collection of "features
>>>>>> objects", which can be stored in a collection of files. The interfaces
>>>>>> to these collections is still under development. Most current and future
>>>>>> work in the CDM is in this category.
>>>>>>
>>>>>> John
>>>>>>
>>>>>> snip ....
>>>>>> _______________________________________________
>>>>>> CF-metadata mailing list
>>>>>> CF-metadata at cgd.ucar.edu
>>>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>>>>>
>>>>>
>>>
>>>
>>
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>
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Received on Sun Apr 29 2012 - 17:33:17 BST
