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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Received on Wed Feb 23 2011 - 19:32:39 GMT
