Rich,
As far as I can tell, the attribute name has always been 'bounds'. I
don't know if it was a find/replace error or what, but the CF
Conventions document uses 'cell_bounds' a couple of times in the body of
the text, even though every example in the document uses 'bounds'. This
is confusing, and should probably be changed.
Grace and peace,
Jim
On 9/19/14, 5:43 PM, Signell, Richard wrote:
> Jim,
>
> Awesome. And I guess if we save it as netcdf4 with deflation, it
> doesn't really matter how large we make the maximum number of vertices
> because all those fillValues at the end will compress very well.
>
> I'm still interested in why we switched from "cell_bounds" to
> "bounds", if indeed we did.
>
> Thanks,
> Rich
>
> On Fri, Sep 19, 2014 at 4:53 PM, Jim Biard <jbiard at cicsnc.org
> <mailto:jbiard at cicsnc.org>> wrote:
>
> Richard,
>
> You can do this. Assuming you are storing the time series for more
> than one watershed, you would have something like this (I lifted
> this largely from Sections 7.1 and 7.2 in the CF Conventions
> document):
>
> dimensions:
> time = -1;
> sheds = 20;
> npoly_verts = 2000; // This would be set to the maximum number
> of vertices for any watershed.
> variable:
> float precip(time, sheds);
> precip.cell_measures = "area: watershed_areas";
> precip.cell_methods = "time area: sum"
> precip.coordinates = "lat lon";
>
> time(time);
> time.axis = "T";
> time.standard_name = "time";
> time.units = "days since ?????";
> time.bounds = "time_bnds";
>
> float lon(cell); // This variable will contain a longitude to
> associate with each watershed. Perhaps the center.
> lon.standard_name = "longitude";
> lon.units = "degrees_east";
> lon.bounds = "watershed_lons";
>
> float lat(cell); // This variable will contain a latitude to
> associate with each watershed. Perhaps the center.
> lat.standard_name = "latitude";
> lat.units = "degrees_north";
> lat.bounds = "watershed_lats";
>
> float watershed_lons(cell, npoly_verts); // This variable will
> have the bounding longitudes for each watershed.
> watershed_lons._FillValue = -999.0; // Use this value for
> unused elements.
>
> float watershed_lats(cell, npoly_verts); // This variable will
> have the bounding latitudes for each watershed.
> watershed_lats._FillValue = -999.0; // Use this value for
> unused elements.
>
> float watershed_areas(cell); // This variable will have the
> area for each watershed.
> watershed_areas.standard_name = "area";
> watershed_areas.units = "km2";
>
> I have left lots of attributes out. I hope this helps.
>
> Grace and peace,
>
> Jim
> On 9/19/14, 4:09 PM, Signell, Richard wrote:
>> Folks,
>> A colleague asked me if a time series of data associated with a
>> polygonal region (e.g. rainfall in a watershed) could be represented
>> in CF.
>>
>> So two questions:
>>
>> 1. Any reason this could be represented as a simple time series with a
>> cell_bounds = lon_verts, lat_verts
>> lon_verts(npoly_verts), lat_verts(npoly_verts)
>>
>> 2. I see an approved ticket from 4 years ago
>> https://cf-pcmdi.llnl.gov/trac/ticket/64
>> with "editorial correction" changing cell_bounds to bounds.
>> Does that mean that CF1.6 we use "cell_bounds" but in CF1.7 we will
>> use "bounds"?
>
> --
> 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's National Climatic Data Center <http://ncdc.noaa.gov/>
> 151 Patton Ave, Asheville, NC 28801
> e: jbiard at cicsnc.org <mailto:jbiard at cicsnc.org>
> o: +1 828 271 4900
>
>
>
>
>
>
>
> --
> Dr. Richard P. Signell (508) 457-2229
> USGS, 384 Woods Hole Rd.
> Woods Hole, MA 02543-1598
--
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's National Climatic Data Center <http://ncdc.noaa.gov/>
151 Patton Ave, Asheville, NC 28801
e: jbiard at cicsnc.org
o: +1 828 271 4900
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Received on Mon Sep 22 2014 - 07:41:23 BST
