Hi Brian,
And I agree that this would be possible since there are not *too* many
different dimensionless coordinates. As you suggested earlier (I
think), the checker should know about all of them.
best regards,
Karl
On 2/23/11 6:32 PM, Brian Eaton wrote:
> Hi Karl,
>
> I agree with all your comments on this thread. In particular, the checker
> shouldn't complain that a, b, a_bnds, and b_bnds don't have units when it
> doesn't have any information that indicates they are dimensional
> quantities.
>
> As an aside though, I do think there would be value in having the CF
> checker be made to recognize when variables are part of the definition of a
> dimensionless vertical coordinate via the formula_terms attribute. In the
> example below, there are two variables called out by formula_terms, p0 and
> ps, which do need to have units in order for the formula to be evaluated
> correctly. The checker could make that check.
>
> Best,
> Brian
>
>
>
> On Wed, Feb 23, 2011 at 05:59:55PM -0800, Karl Taylor wrote:
>> This all looks correct to me.
>>
>> Karl
>>
>> On 2/23/11 10:59 AM, Kyle Olivo wrote:
>>>> So I'm wondering
>>>> whether the coordinate variable, lev(lev), has the standard_name and
>>>> formula_terms attributes that should allow the checker to recognize them.
>>> From the file:
>>>> double lev(lev) ;
>>>> lev:bounds = "lev_bnds" ;
>>>> lev:units = "1" ;
>>>> lev:axis = "Z" ;
>>>> lev:positive = "down" ;
>>>> lev:long_name = "hybrid sigma pressure coordinate" ;
>>>> lev:standard_name =
>>>> "atmosphere_hybrid_sigma_pressure_coordinate" ;
>>>> lev:formula = "p = a*p0 + b*ps" ;
>>>> lev:formula_terms = "p0: p0 a: a b: b ps: ps" ;
>>>> double lev_bnds(lev, bnds) ;
>>>> lev_bnds:formula = "p = a*p0 + b*ps" ;
>>>> lev_bnds:standard_name =
>>>> "atmosphere_hybrid_sigma_pressure_coordinate" ;
>>>> lev_bnds:units = "1" ;
>>>> lev_bnds:formula_terms = "p0: p0 a: a_bnds b: b_bnds
>>>> ps: ps" ;
>>> - Kyle
>>>
>>> On 02/23/2011 01:37 PM, Brian Eaton wrote:
>>>> The checker also didn't recognize that the "a" and "b" variables are being
>>>> used to describe a dimensionless vertical coordinate. So I'm wondering
>>>> whether the coordinate variable, lev(lev), has the standard_name and
>>>> formula_terms attributes that should allow the checker to recognize them.
>>>>
>>>> Brian
>>>>
>>>>
>>>> On Wed, Feb 23, 2011 at 06:17:01PM +0000, Jonathan Gregory wrote:
>>>>> Dear Karl et al
>>>>>
>>>>> To me it looks like the checker couldn't tell that they were bounds variables,
>>>>> because there is no bounds attribute pointing to them. They look like data
>>>>> variables.
>>>>>
>>>>> Best wishes
>>>>>
>>>>> Jonathan
>>>>>
>>>>> On Wed, Feb 23, 2011 at 09:48:21AM -0800, Karl Taylor wrote:
>>>>>> Date: Wed, 23 Feb 2011 09:48:21 -0800
>>>>>> From: Karl Taylor<taylor13 at llnl.gov>
>>>>>> User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US;
>>>>>> rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7
>>>>>> To: Kyle Olivo<Kyle.Olivo at noaa.gov>
>>>>>> CC: aparna Radhakrishnan<Aparna.Radhakrishnan at noaa.gov>,
>>>>>> "cf-metadata at cgd.ucar.edu"<cf-metadata at cgd.ucar.edu>, "Doutriaux,
>>>>>> Charles"<doutriaux1 at llnl.gov>
>>>>>> Subject: Re: [CF-metadata] CF Standards
>>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> If a, b, a_bnds, and b_bnds are dimensionless (and I think they
>>>>>> are), then CF should not raise an error that "no units attribute
>>>>>> set". Does anyone disagree?
>>>>>>
>>>>>> thanks,
>>>>>> Karl
>>>>>>
>>>>>> On 2/23/11 6:55 AM, Kyle Olivo wrote:
>>>>>>> Hi Charles,
>>>>>>>
>>>>>>> We recently CMORized the Amon variable clw and noticed that the output
>>>>>>> doesn't seem to adhere to CF standards.
>>>>>>>
>>>>>>>> double a_bnds(lev, bnds) ;
>>>>>>>> a_bnds:long_name = "vertical coordinate formula term:
>>>>>>>> a(k+1/2)" ;
>>>>>>>> double b_bnds(lev, bnds) ;
>>>>>>>> b_bnds:long_name = "vertical coordinate formula term:
>>>>>>>> b(k+1/2)" ;
>>>>>>>> double a(lev) ;
>>>>>>>> a:long_name = "vertical coordinate formula term: a(k)" ;
>>>>>>>> double b(lev) ;
>>>>>>>> b:long_name = "vertical coordinate formula term: b(k)" ;
>>>>>>> CF-Checker results:
>>>>>>>
>>>>>>>> ------------------
>>>>>>>> Checking variable: a
>>>>>>>> ------------------
>>>>>>>> ERROR (3.1): No units attribute set
>>>>>>>> ------------------
>>>>>>>> Checking variable: a_bnds
>>>>>>>> ------------------
>>>>>>>> ERROR (3.1): No units attribute set
>>>>>>>> ------------------
>>>>>>>> Checking variable: b
>>>>>>>> ------------------
>>>>>>>> ERROR (3.1): No units attribute set
>>>>>>>> ------------------
>>>>>>>> Checking variable: b_bnds
>>>>>>>> ------------------
>>>>>>>> ERROR (3.1): No units attribute set
>>>>>>> Any advice on how to proceed on this? Should a units value of some kinds
>>>>>>> have been included in the Amon MIP table?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Kyle
>>>>>>>
>>>>>> _______________________________________________
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>>>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>>>>> _______________________________________________
>>>>> CF-metadata mailing list
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