Hi Charlie, > the strings "maximum_absolute_value", "minimum_absolute_value", > and "mean_absolute_value". I suggest CF adopt this, or some > variant pursuant to discussion.
Many apologies - for some reason, I failed to register this crucial sentence when I replied. I suppose that it's good that the same names were arrived at without prior knowledge. No objections from me, then. All the best, David ---- Original message from Charlie Zender (04PM 19 Feb 15) > Date: Thu, 19 Feb 2015 16:39:15 -0800 > From: Charlie Zender <[email protected]> > To: David Hassell <[email protected]> > CC: CF Metadata Mail List <[email protected]> > Subject: Re: [CF-metadata] New cell_methods: mabs/mibs/mebs? > User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 > Thunderbird/31.4.0 > > Hello David, > > I use mabs/mebs/mibs as shorthand, not as cell_methods. > I suggest, and NCO implements, cell_methods with the longer > versions that you prefer. The command line operators of NCO > accept either full or abbreviated versions (to save typing > when conducting the operation itself). > > Now I see what you mean by the sentence in the appendix. > It could be read either way, and I read it the wrong way. > So I like your suggestion to clarify it. > > Charlie > > On 02/19/2015 04:27 PM, David Hassell wrote: > >Dear Charlie, > > > >I for one have no objection, in general, to new cell methods - I don't > >think that there are enough. > > > >Your suggestions (mabs/mibs/mebs) are clearly well defined, though I'm > >personally not so keen on the use of abbreviations. I've not seen > >these terms before, and wouldn't have guessed what they all mean. This > >is contrary to all of the other cell methods, which are unabbreviated > >and, I suspect, nearly universally understood. > > > >I dislike typing as much as anyone, but spelling them out is only 1 to > >4 characters more than typing standard_deviation, the current longest > >method name: > > > >standard_deviation > >mean_absolute_value > >minimum_absolute_value > >maximum_absolute_value > > > >These terms seem nicely self describing to me. Do you think this is an > >option? > > > >>There appears to be an error in the draft 1.7 document. The sentence > >>describing Appendix E (the cell-methods appendix) says "In the Units > >>column, u indicates the units of the physical quantity before the > >>method is applied." Actually the units column entries are valid > >>_after_ the method is applied. Variance is the only method for which > >>this currently matters. This can be addressed independently of the > >>rest of the cell_methods suggestions proposed here. > > > >I think that this is OK. The column contains units after the method is > >applied, defined in terms of the original units ('u'). However, I > >agree that the terse description can mislead (as it did me just > >now!). How about replacing: > > > > "In the Units column, 'u' indicates the units of the physical > > quantity before the method is applied." > > > >with something like: > > > > "The Units column contains the units of the physical quantity after > > the method is applied, in terms of 'u', the units before the method > > is applied." > > > > > >All the best, > > > >David > > > > > >---- Original message from Charlie Zender (11AM 19 Feb 15) > > > >>Date: Thu, 19 Feb 2015 11:56:22 -0800 > >>From: Charlie Zender <[email protected]> > >>To: CF Metadata Mail List <[email protected]> > >>Subject: [CF-metadata] New cell_methods: mabs/mibs/mebs? > >>User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) > >> Gecko/20100101 Thunderbird/31.4.0 > >> > >>Dear CF-ers, > >> > >>The statistics mabs/mibs/mebs stand for "Maximum absolute value", > >>"Minimum absolute value", and "Mean absolute value", respectively. > >>They are similar to max/min/mean statistics, and they can be useful > >>in characterizing data when one wants positive-definite metrics. > >>mebs (unlike mean) does not allow positive and negative values to > >>compensate eachother. Unlike rms, mebs not does weight outliers > >>quadratically. NCO (version 4.4.8) implements mabs/mibs/mebs as > >>fundamental statistics (like max/min/mean/rms), and annotates the > >>cell_methods attribute of variables reduced by these statistics with > >>the strings "maximum_absolute_value", "minimum_absolute_value", and > >>"mean_absolute_value". I suggest CF adopt this, or some variant > >>pursuant to discussion. > >> > >>So I guess this is a request for discussion. > >>The relevant portions of CF are > >>http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/build/cf-conventions.html#cell-methods > >>http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/build/cf-conventions.html#appendix-cell-methods > >>The modifications that would be needed seem straightforward: > >>mention mabs/mebs/mibs in the text and then enlarge the existing > >>cell_methods table table by three rows. > >> > >>There appears to be an error in the draft 1.7 document. The sentence > >>describing Appendix E (the cell-methods appendix) says "In the Units > >>column, u indicates the units of the physical quantity before the > >>method is applied." Actually the units column entries are valid > >>_after_ the method is applied. Variance is the only method for which > >>this currently matters. This can be addressed independently > >>of the rest of the cell_methods suggestions proposed here. > > > >I think that this is OK. The column contains units after the method is > >applied, defined in terms of the original units ('u'). However, the > >terse description is misleading on first reading. How about something > >like: > > > >"In the Units column are the units of the physical quantity after the > > method is applied, in terms of 'u', the units before the method is > > applied." > > > >>Best, > >>Charlie > >>-- > >>Charlie Zender, Earth System Sci. & Computer Sci. > >>University of California, Irvine 949-891-2429 )'( > >>_______________________________________________ > >>CF-metadata mailing list > >>[email protected] > >>http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > > > >-- > >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: [email protected] > > > > -- > Charlie Zender, Earth System Sci. & Computer Sci. > University of California, Irvine 949-891-2429 )'( -- 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: [email protected] _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
