[CF-metadata] Overlapping vertical bounds

Ansley C. Manke ansley.b.manke at noaa.gov
Fri Mar 3 16:59:47 MST 2017


Hi Evan,

The data model in Ferret does not allow for overlapping bounds, nor does 
it allow non-contiguous bounds.  Those are legal in CF, but Ferret (as I 
imagine is the case for most software), does not implement everything in 
the standard.

In fact Ferret will not make use of your bounds definition; I believe it 
will have ignored the bounds and will instead have defined the grid-cell 
edges using the midpoints between axes.  Use the command,

    show axis/z axis_name

to see what Ferret has done to set up its the internal representation of 
the axis.

-Ansley


On 3/3/2017 7:32 AM, Manning, Evan M (398B) wrote:
>
> When I was researching  the topic I came across this:
>
> >/When I try and load the file using Ferret, this throws a warning.. Which/
>
> >/makes me think I¹m not doing things correctly:/
>
> >//
>
> >/Ferret v6.93/
>
> >/yes? use file.nc/
>
> >/   *** NOTE: Axis definition error on axis: time. Bounds describe 
> cells that/
>
> >/overlap one another/
>
> which made me think that overlap was an error.  But reading more 
> context I see it is just a “note”, not an “error”, and clearly 
> overlapping bounds are accepted.
>
> For my situation of overlapping vertical trapezoids, I now think I 
> should use the full overlapping extent in the “bounds” variable and 
> explain the full shape of the trapezoids in the main variable’s 
> description attribute.
>
> Is there a better way to communicate the full situation?
>
>   -- Evan
>
> *From: *Jim Biard <jbiard at cicsnc.org>
> *Date: *Friday, March 3, 2017 at 5:09 AM
> *To: *<cf-metadata at cgd.ucar.edu>
> *Subject: *Re: [CF-metadata] Overlapping vertical bounds
>
> What makes you think overlapping bounds are illegal?
>
> On 3/2/17 7:20 PM, Manning, Evan M (398B) wrote:
>
>     I have some quantities which are defined on trapezoids in the
>     vertical direction.
>
>     For example the top trap might be full weight from the top of the
>     atmosphere (TOA) to 50 hPa, then we ramp linearly between the
>     first and second traps between 50 & 75 hPa, then trap 2 is full
>     weight 75-100 hPa, followed by another transition in [100, 125]
>     hPa, etc.
>
>     I can’t have a bounds variable with the full extent of each trap
>     like [ [0, 75], [50, 125], [100, … because overlap is illegal.
>
>     I could have underlap, just giving the intervals where each trap
>     is in full force: [ [0, 50], [75, 100], …
>
>     Or I could use the midpoints of the transitions: [ [ 0, 62.5],
>     [62.5, 112.5], …
>
>     I’d prefer to find a standard way to communicate the precise
>     situation.  Is there one?
>
>       -- Evan
>
>
>
>
>     _______________________________________________
>
>     CF-metadata mailing list
>
>     CF-metadata at cgd.ucar.edu <mailto:CF-metadata at cgd.ucar.edu>
>
>     http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
> -- 
>
> *ICS-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: jbiard at cicsnc.org <mailto:jbiard at 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 at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cgd.ucar.edu/pipermail/cf-metadata/attachments/20170303/8e7b217e/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 15785 bytes
Desc: not available
URL: <http://mailman.cgd.ucar.edu/pipermail/cf-metadata/attachments/20170303/8e7b217e/attachment-0001.png>


More information about the CF-metadata mailing list