Dear Alison and all, I support Martin's proposal http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/020666.html to add
indian_pacific_ocean atlantic_arctic_ocean to the list of standard regions labels. best regards, Karl On 11/21/18 1:40 PM, Martin Juckes - UKRI STFC wrote: > Dear Jim, > > > sorry, I stand corrected. Thank you for the detailed explanation. > > > The conformance statements looks to be in error. > > > Is there a clear rule for what makes a valid set of flag_values when used in > conjunction with flag_masks? > > > regards, > > Martin > > > ________________________________ > From: Jim Biard <[email protected]> > Sent: 21 November 2018 20:50 > To: Juckes, Martin (STFC,RAL,RALSP); [email protected] > Subject: Re: [CF-metadata] Multiple zeros in flag_values allowed? > > > Martin, > > The two subfields are independent. You can have very bad quality data and > very bad weather at the same time. And that's how the flag masks and flag > values are supposed to work. The mask splits off bit regions that are > independent of one another. There is no ambiguity. > > The possible options and the values masked by the flag masks of 3 (binary > 0011) and 12 (binary 1100) are: > > Weather Quality > Binary Value > Binary value & 3 > Binary value & 12 > > very bad > very bad > 0000 > 0 > 0 > > very bad > bad > 0001 > 1 > 0 > > very bad > good > 0010 > 2 > 0 > > very bad > very good > 0011 > 3 > 0 > > bad very bad 0100 > 0 > 4 > > bad bad 0101 > 1 > 4 > > bad good 0110 > 2 > 4 > > bad very good 0111 > 3 > 4 > > good very bad 1000 > 0 > 8 > > good bad 1001 > 1 > 8 > > good good 1010 > 2 > 8 > > good > very good 1011 > 3 > 8 > > very good very bad 1100 > 0 > 12 > > very good bad 1101 > 1 > 12 > > very good good 1110 > 2 > 12 > > very good very good 1111 > 3 > 12 > > > Grace and peace, > > Jim > > On 11/21/18 12:03 PM, Martin Juckes - UKRI STFC wrote: > > Hello Jim, Julien, > > > I'm not sure .. I think the conformance might be right here and your > flag_values should be 0,1,2,3, 4, 8,12,16, and flag_masks 3,3,3,3,28,28,28,28 > > > If, for instance, you very_bad_quality and very_bad_weather, then "var" > should have value 4 = '00100000` in binary. Masked with 3 (11000000) gives > zero, and masked with 28 (00111000) gives 4. Re-using the zero value would > make zero ambiguous, so you need to start the 2nd sequence at 4. > > > regards, > > Martin > > ________________________________ > From: CF-metadata > <[email protected]><mailto:[email protected]> > on behalf of Jim Biard <[email protected]><mailto:[email protected]> > Sent: 20 November 2018 16:51:24 > To: [email protected]<mailto:[email protected]> > Subject: Re: [CF-metadata] Multiple zeros in flag_values allowed? > > > Julien, > > That's fine. The conformance document probably needs a better statement of > the requirement when flag masks are used. > > Grace and peace, > > Jim > > On 11/20/18 11:40 AM, Julien Demaria wrote: > Hi, > > We want to define a flags variable defining like that: > var:flag_masks = 3, 3, 3, 3, 12, 12, 12, 12 ; > var:flag_values = 0, 1, 2, 3, 0, 4, 8, 12 ; > var:flag_meanings = “very_bad_quality bad_quality good_quality > very_good_quality > very_bad_weather bad_weather > good_weather very_good_weather” ; > > I understand from http://cfconventions.org/Conformance/conformance.html that > it is not allowed to use several time the same value (here zero) in > flag_values: > > Requirements: > > · The flag_values attribute values must be mutually exclusive among > the set of flag_values attribute values defined for that variable. > So it means that for each new “bits combination” in the flags definition we > lost one of the combination because we cannot use zero more than one time? > Do you confirm this? What is the reason? > > Thanks in advance, > Julien > > > > > _______________________________________________ > CF-metadata mailing list > [email protected]<mailto:[email protected]><mailto:[email protected]><mailto:[email protected]> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > -- > [CICS-NC] <http://www.cicsnc.org/><http://www.cicsnc.org/> Visit us on > Facebook <http://www.facebook.com/cicsnc><http://www.facebook.com/cicsnc> > Jim Biard > Research Scholar > Cooperative Institute for Climate and Satellites NC > <http://cicsnc.org/><http://cicsnc.org/> > North Carolina State University <http://ncsu.edu/><http://ncsu.edu/> > NOAA National Centers for Environmental Information > <http://ncdc.noaa.gov/><http://ncdc.noaa.gov/> > formerly NOAA’s National Climatic Data Center > 151 Patton Ave, Asheville, NC 28801 > e: > [email protected]<mailto:[email protected]><mailto:[email protected]><mailto:[email protected]> > o: +1 828 271 4900 > > Connect with us on Facebook for > climate<https://www.facebook.com/NOAANCEIclimate><https://www.facebook.com/NOAANCEIclimate> > and ocean and > geophysics<https://www.facebook.com/NOAANCEIoceangeo><https://www.facebook.com/NOAANCEIoceangeo> > information, and follow us on Twitter at > @NOAANCEIclimate<https://twitter.com/NOAANCEIclimate><https://twitter.com/NOAANCEIclimate> > and > @NOAANCEIocngeo<https://twitter.com/NOAANCEIocngeo><https://twitter.com/NOAANCEIocngeo>. > > > > -- > [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: [email protected]<mailto:[email protected]> > 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 > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
