Folks, I'm confused now. Are we proposing that we could have CF-compliant files that have no valid coordinate data, with the justification that somebody may figure the coordinates out later?
-Rich On Thu, Mar 29, 2012 at 1:01 PM, Steve Hankin <steven.c.han...@noaa.gov> wrote: > Returning to Nan's valid example, the proposed wording isn't very attuned to > the valid needs of (in situ) observations. If the pressure sensor fails, > while other sensors remain active, then the Z auxiliary coordinate becomes > unknown but other parameters remain valid. The observations have > potential value (though greatly degraded, of course), because a future > investigator may figure out how to estimate the Z position from other > information. For the investigator writing those applications, the > statements below are wrong or misleading. > > I think the right thing to say is something along the lines of > > "Application writers should be aware that under some (rare) circumstances > data auxiliary coordinate values may be missing, while other parameters at > the corresponding indices remain valid. While special purpose applications > may be able to glean useful information at these indices, most applications > will want to regard data as missing where the auxiliary coordinates are > missing " > > > On 3/29/2012 9:05 AM, Jim Biard wrote: > > All, > > For the work I am doing right now, I am required to not fill in missing > values in any variable. I encourage everyone to go with John Caron's idea. > > Grace and peace, > > Jim > > > On Thu, Mar 29, 2012 at 12:01 PM, John Caron <ca...@unidata.ucar.edu> wrote: >> >> To answer this concern, I would agree to modify the statement >> >> "Applications are free to assume that data is missing where the auxiliary >> coordinates are missing" >> >> to >> >> >> "Applications should treat the data as missing where the auxiliary >> coordinates are missing" >> >> My concern is that we shouldnt make a file "non CF compliant" just because >> the data provider would like to store data values where there arent >> coordinate values. But telling them that standard software _will_ ignore >> them seems good. >> >> >> >> >> On 3/29/2012 9:47 AM, Rich Signell wrote: >>> >>> Jonathan, >>> >>> +1 on your idea of only identifying variables as aux coordinate >>> variables once they have valid values at valid data locations. >>> >>> -Rich >>> >>> On Thu, Mar 29, 2012 at 11:32 AM, Jonathan Gregory >>> <j.m.greg...@reading.ac.uk> wrote: >>>> >>>> Dear Jim >>>> >>>> We are discussing auxiliary coordinate variables. They do not have to be >>>> 1D or monotonic. Those requirements apply to coordinate variables in the >>>> Unidata sense. CF distinguishes these two concepts in Sect 1.2. >>>> >>>>> The point is, the information in the variable *is* coordinate >>>>> information, >>>> >>>> I would say, if it's missing, it's not information. >>>> >>>>> What if we say something along the lines of, "Applications should treat >>>>> the >>>>> data as missing where the auxiliary coordinates are missing when >>>>> plotting >>>>> data."? Would that resolve the problem? >>>> >>>> Plotting is not the only thing that an application might wish to use it >>>> for. >>>> If we said, more generally, "Applications should treat the data as >>>> missing for >>>> all purposes where the aux coord variables are missing", it would be >>>> almost >>>> the same as not allowing missing data in aux coord vars, since there >>>> would be >>>> no point in providing a data value if it was not permitted to use it. >>>> >>>> Although I am arguing one side, I could be convinced either way. But it >>>> does >>>> feel unsafe to me at present. >>>> >>>> Cheers >>>> >>>> Jonathan >>>> _______________________________________________ >>>> CF-metadata mailing list >>>> CF-metadata@cgd.ucar.edu >>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >>> >>> >>> >> >> _______________________________________________ >> CF-metadata mailing list >> CF-metadata@cgd.ucar.edu >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > > > -- > Jim Biard > Research Scholar > Cooperative Institute for Climate and Satellites > Remote Sensing and Applications Division > National Climatic Data Center > 151 Patton Ave, Asheville, NC 28801-5001 > > jim.bi...@noaa.gov > 828-271-4900 > > > > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > -- Dr. Richard P. Signell (508) 457-2229 USGS, 384 Woods Hole Rd. Woods Hole, MA 02543-1598 _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata