CF section 2.2 already clarifies that it is the "last" (AKA "rightmost") dimension that specifies the maximum number of characters and is collapsed to interpret the char array as a String array: > > An n-dimensional array of strings must be implemented as a character array > of dimension (n,max_string_length), with the last (most rapidly varying) > dimension declared large enough to contain the longest string in the array. > All the strings in a given array are therefore defined to be equal in > length. For example, an array of strings containing the names of the months > would be dimensioned (12,9) in order to accommodate "September", the month > with the longest name.
My proposed change does not alter that text. On Mon, Feb 27, 2017 at 4:58 PM, Chris Barker <chris.bar...@noaa.gov> wrote: > On Wed, Feb 22, 2017 at 11:38 AM, Bob Simons - NOAA Federal < > bob.sim...@noaa.gov> wrote: > >> >>> We need to either specify the "string" dimension, or have a consistent >>> convention: >>> >>> A 10x8 CHAR array could be either 10 8 character strings or 8 ten >>> character strings. And it gets more confusing with higher dimensions. >>> >> >> There is no standard naming system in CF to denote a String dimension >> (ie, the number of chars, vs a char array). That is a different approach to >> solving the problem. I don't like that approach as much because so many >> people have written so much software that writes and reads files using >> dimension names of their choice. I don't want to tell everyone to rewrite >> all their exiting files and software/scripts to read/write those files in >> order to comply with new CF rules. >> >> Instead, I'm proposing a separate, new attribute (data_type=string|char), >> partly because it doesn't interfere with existing dimension names or >> attribute names. >> > > I wasn't clear -- even if you know a CHAR array is supposed to be an array > of strings, you don't know which dimension is the "string" dimension, and > which is the array dimension. If you have a 3x4 array of length-5 strings, > what is your CHAR array dimension? either of these would make sense: > > (3,4,5) > (5,3,4) > and > (3,5,4) would be possible, though a bit insane :-) > > even worse, if you see a "string" array that has dimensions of (3,4,5) > what is that? and (3,4) array of length-5 strings? a (4,5) array or length > 3 strings? > > -CHB > > -- > > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > chris.bar...@noaa.gov > -- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 99 Pacific St., Suite 255A (New!) Monterey, CA 93940 (New!) Phone: (831)333-9878 (New!) Fax: (831)648-8440 Email: bob.sim...@noaa.gov The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <><
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