oops, sorry misread the question On Mon, Dec 21, 2015 at 1:06 PM, Jim Biard <jbi...@cicsnc.org> wrote:
> John, > > But ancillary variables aren't coordinates, are they? > > Jim > > > On 12/21/15 1:08 PM, John Caron wrote: > > i think a crucial property of coordinates is that their dimensions are a > subset of the variable's dimensions. otherwise one cant assign the correct > coordinate. > > the length of a char valued coordinate is an exception, really char(n) is > logically the same as string. > > while a dim=1 coordinate could be used, it would violate that simple > principle for no obvious gain. scalar here is preffered i think. > > we added some language to CF recently to clarify this. not sure where it > is. > > john > > > > On Mon, Dec 21, 2015 at 8:49 AM, Jim Biard <jbi...@cicsnc.org> wrote: > >> David, >> >> I've not come across this particular case, but I've had cases where the >> ancillary data that I wish to store has less dimensions than the >> corresponding parent field. The Conventions seem to require that the >> dimensions all match. I'm of the opinion that it should not be so >> restrictive. >> >> In your particular instance, what is the significance of your time >> variable? >> >> Grace and peace, >> >> Jim >> >> >> On 12/21/15 10:41 AM, David Hassell wrote: >> >> Hello, >> >> I was wondering if anyone has ever had use for an ancillary variable >> (or data variable pointed to from a formula_terms attribute), having a >> size 1 dimension which the "parent" field does *not* have. The >> convention do not say anything about this. >> >> For example: >> >> dimensions: >> t = 1; >> x = 96; >> y = 73; >> >> variables: >> float q(x, y) ; >> q:standard_name = "specific_humidity" ; >> q:units = "g/g" ; >> q:ancillary_variables = "q_error_limit" ; >> >> float q_error_limit(t, x, y) >> q_error_limit:standard_name = "specific_humidity standard_error" ; >> q_error_limit:units = "g/g" ; >> >> >> Similary for a scalar coordinate variable, which is logically >> equivalent to the size 1 dimension case (this time shown on a formula >> terms variable): >> >> dimensions: >> x = 96; >> y = 73; >> z = 19; >> >> variables: >> float q(z, x, y) ; >> q:standard_name = "specific_humidity" ; >> q:units = "g/g" ; >> >> float z(z): >> z:standard_name = "atmosphere_hybrid_height_coordinate"; >> z.formula_terms = "a: var1 b: var2 orog: var3" >> >> float var3(x, y): >> time:coordinates = "time"; >> >> float time: >> time:standard_name = "time"; >> time:units = "days since 2000-12-1"; >> >> >> Thanks for your help, >> >> All the best, >> >> David >> >> >> -- >> David Hassell >> National Centre for Atmospheric Science (NCAS) >> Department of Meteorology, University of Reading, >> Earley Gate, PO Box 243, >> Reading RG6 6BB, U.K. >> >> Tel : +44 118 3785613 >> E-mail: d.c.hass...@reading.ac.uk >> _______________________________________________ >> CF-metadata mailing >> listcf-metad...@cgd.ucar.eduhttp://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> >> -- >> [image: CICS-NC] <http://www.cicsnc.org/> Visit us on >> Facebook <http://www.facebook.com/cicsnc> *Jim Biard* >> *Research Scholar* >> Cooperative Institute for Climate and Satellites NC <http://cicsnc.org/> >> North Carolina State University <http://ncsu.edu/> >> NOAA National Centers for Environmental Information >> <http://ncdc.noaa.gov/> >> *formerly NOAA’s National Climatic Data Center* >> 151 Patton Ave, Asheville, NC 28801 >> e: jbi...@cicsnc.org >> o: +1 828 271 4900 >> >> *Connect with us on Facebook for climate >> <https://www.facebook.com/NOAANCEIclimate> and ocean and geophysics >> <https://www.facebook.com/NOAANCEIoceangeo> information, and follow us on >> Twitter at @NOAANCEIclimate <https://twitter.com/NOAANCEIclimate> and >> @NOAANCEIocngeo <https://twitter.com/NOAANCEIocngeo>. * >> >> _______________________________________________ >> CF-metadata mailing list >> CF-metadata@cgd.ucar.edu >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> > > > _______________________________________________ > CF-metadata mailing > listcf-metad...@cgd.ucar.eduhttp://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > -- > [image: CICS-NC] <http://www.cicsnc.org/> Visit us on > Facebook <http://www.facebook.com/cicsnc> *Jim Biard* > *Research Scholar* > Cooperative Institute for Climate and Satellites NC <http://cicsnc.org/> > North Carolina State University <http://ncsu.edu/> > NOAA National Centers for Environmental Information > <http://ncdc.noaa.gov/> > *formerly NOAA’s National Climatic Data Center* > 151 Patton Ave, Asheville, NC 28801 > e: jbi...@cicsnc.org > o: +1 828 271 4900 > > *Connect with us on Facebook for climate > <https://www.facebook.com/NOAANCEIclimate> and ocean and geophysics > <https://www.facebook.com/NOAANCEIoceangeo> information, and follow us on > Twitter at @NOAANCEIclimate <https://twitter.com/NOAANCEIclimate> and > @NOAANCEIocngeo <https://twitter.com/NOAANCEIocngeo>. * > > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > >
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