[netCDFJava #RIZ-451320]: why can't this be read as a grid

Hi Don:

Sorry, it was a different bug that got into 4.3.22:

 
https://www.unidata.ucar.edu/esupport/staff/index.php?_m=tickets&_a=viewticket&ticketid=23906&departmentid=22&ticketstatusid=3

Havent had a chance to backport this one, you could do it or start using 4.5 
(recommended).

John

> What did you find out?
> 
> On 5/27/14 3:34 PM, Unidata netCDF Java Support wrote:
> > I think there was a intercommunication between sean and me. ill check on it.
> >
> > John
> >
> >> I just tried the released 4.3.22 version and still cannot read this
> >> grid.  The changes did not get put on the 4.3.22 release as promised.
> >>
> >> Don
> >>
> >> On 5/21/14 3:54 PM, Don Murray (NOAA Affiliate) wrote:
> >>> John-
> >>>
> >>> I've checked out and built the 4.3.22 branch, , but still cannot read
> >>> the files that have grid_latitude/grid_longitude as standard names in as
> >>> a grid in ToolsUI.
> >>>
> >>> I can read it in if I build the 4.5 branch.
> >>>
> >>> Don
> >>>
> >>> On 5/21/14 1:44 PM, Unidata netCDF Java Support wrote:
> >>>> Its on 4.3.22, will be released soon.
> >>>>
> >>>>> John-
> >>>>>
> >>>>> I contacted the CDO developers and apparently this is fixed in the
> >>>>> latest version of CDO (1.6.3), but I'm stuck at 1.6.2 until it makes it
> >>>>> out to macports.  I see that you fixed this in the 4.5 branch.  Can it
> >>>>> get merged into the 4.3.22 branch so I test it out?
> >>>>>
> >>>>> Thanks.
> >>>>>
> >>>>> Don
> >>>>>
> >>>>> On 5/17/14 1:03 PM, Unidata netCDF Java Support wrote:
> >>>>>> Hi Don:
> >>>>>>
> >>>>>> We will have a look to see if we can safely disambiguate the
> >>>>>> conflicting info. Can you contact CDO and let them know they have a
> >>>>>> bug?
> >>>>>>
> >>>>>> thanks
> >>>>>> John
> >>>>>>
> >>>>>>> Dear Lansing, John and Ethan-
> >>>>>>>
> >>>>>>> Thanks for your responses.  I had read the CF conventions about the
> >>>>>>> standard names and understand that grid_latitude/grid_longitude are
> >>>>>>> the
> >>>>>>> standard names for a rotated pole projection.  That's why I
> >>>>>>> indicated to
> >>>>>>> Lansing that this was the problem.
> >>>>>>>
> >>>>>>> However, as Ethan points out, the units are wrong for a
> >>>>>>> rotated_pole and
> >>>>>>> there is no grid_mapping_name variable associated with the tas
> >>>>>>> variable.
> >>>>>>> So, tas is not defined by a rotated pole coordinate system.
> >>>>>>>
> >>>>>>> The original grid is a gaussian dataset and the original standard
> >>>>>>> names
> >>>>>>> were latitude and longitude, so CDO does change the standard names.
> >>>>>>>
> >>>>>>>    From my perspecitve, though, the latitude and longitude variables
> >>>>>>> meet
> >>>>>>> the requirements for being standard latitude and longitude
> >>>>>>> variables in
> >>>>>>> CF by the units and axis attributes:
> >>>>>>>
> >>>>>>> http://cfconventions.org/1.6.html#latitude-coordinate
> >>>>>>>
> >>>>>>> (correct units and axis attributes) much more than for the rotated
> >>>>>>> pole
> >>>>>>> case (wrong units, no grid_mapping_name).  So, I would still content
> >>>>>>> that this is a bug.
> >>>>>>>
> >>>>>>> Don
> >>>>>>>
> >>>>>>> On 5/16/14 4:43 PM, Unidata netCDF Java Support wrote:
> >>>>>>>> Hi Don,
> >>>>>>>>
> >>>>>>>> The use of "grid_latitude" and "grid_longitude" standard names
> >>>>>>>> indicates a rotated pole grid mapping (defined in Appendix F:
> >>>>>>>> "Grid Mappings" section [1] of the CF spec). But lat and lon have
> >>>>>>>> the wrong units for a rotated pole grid (they should be "degrees")
> >>>>>>>> and a rotated pole grid mapping is not defined. (Here's the
> >>>>>>>> definition for "grid_latitude" [2] from the CF standard name table
> >>>>>>>> [3].)
> >>>>>>>>
> >>>>>>>> Was the original dataset on a rotated pole grid?
> >>>>>>>>
> >>>>>>>> Ethan
> >>>>>>>>
> >>>>>>>> [1] http://cfconventions.org/1.6.html#appendix-grid-mappings
> >>>>>>>>
> >>>>>>>> [2] "Latitude is positive northward; its units of degree_north (or
> >>>>>>>> equivalent) indicate this explicitly. In a latitude-longitude
> >>>>>>>> system defined with respect to a rotated North Pole, the standard
> >>>>>>>> name of grid_latitude should be used instead of latitude. Grid
> >>>>>>>> latitude is positive in the grid-northward direction, but its
> >>>>>>>> units should be plain degree."
> >>>>>>>>
> >>>>>>>> [3]
> >>>>>>>> https://badc.nerc.ac.uk/help/formats/netcdf/cf-standard-name-table.html
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> Don Murray wrote:
> >>>>>>>>> It doesn't like the standard_name for latitude and longitude
> >>>>>>>>> (using ncml
> >>>>>>>>> to remove them makes the grid readable).  I don't have the
> >>>>>>>>> ability to
> >>>>>>>>> remove them in the workflow, and this seems like a bug.
> >>>>>>>>>
> >>>>>>>>> Don
> >>>>>>>>>
> >>>>>>>>> On 5/16/14 3:35 PM, Unidata netCDF Java Support wrote:
> >>>>>>>>>> There's confusion somewhere, ToolsUI is looking for a projection
> >>>>>>>>>> instead
> >>>>>>>>>> of recognizing the lat lon coords.
> >>>>>>>>>>
> >>>>>>>>>> -Lansing
> >>>>>>>>>>
> >>>>>>>>>> On 5/16/2014 12:55 PM, Don Murray (NOAA Affiliate) wrote:
> >>>>>>>>>>> New Ticket: why can't this be read as a grid
> >>>>>>>>>>>
> >>>>>>>>>>> Hi-
> >>>>>>>>>>>
> >>>>>>>>>>> I have a netCDF file that I created using the Climate Data
> >>>>>>>>>>> Operators
> >>>>>>>>>>> (CDO) package by subsetting a larger file.  The original file
> >>>>>>>>>>> can be
> >>>>>>>>>>> read into the IDV/ToolsUI, but the subset cannot (is not
> >>>>>>>>>>> recognized as a
> >>>>>>>>>>> grid).  I don't see anything obviously wrong with the file,
> >>>>>>>>>>> except that
> >>>>>>>>>>> maybe the CDM is getting confused by the use of x and y?
> >>>>>>>>>>>
> >>>>>>>>>>> Why doesn't the CDM recognize this as a grid?
> >>>>>>>>>>>
> >>>>>>>>>>> Don
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> Ticket Details
> >>>>>>>> ===================
> >>>>>>>> Ticket ID: RIZ-451320
> >>>>>>>> Department: Support netCDF Java
> >>>>>>>> Priority: Normal
> >>>>>>>> Status: Closed
> >>>>>>>>
> >>>>>>>
> >>>>>>> --
> >>>>>>> Don Murray
> >>>>>>> NOAA/ESRL/PSD and CIRES
> >>>>>>> 303-497-3596
> >>>>>>> http://www.esrl.noaa.gov/psd/people/don.murray/
> >>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Ticket Details
> >>>>>> ===================
> >>>>>> Ticket ID: RIZ-451320
> >>>>>> Department: Support netCDF Java
> >>>>>> Priority: Normal
> >>>>>> Status: Open
> >>>>>>
> >>>>>
> >>>>> --
> >>>>> Don Murray
> >>>>> NOAA/ESRL/PSD and CU-CIRES
> >>>>> 303-497-3596
> >>>>> http://www.esrl.noaa.gov/psd/people/don.murray/
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>> Ticket Details
> >>>> ===================
> >>>> Ticket ID: RIZ-451320
> >>>> Department: Support netCDF Java
> >>>> Priority: Normal
> >>>> Status: Closed
> >>>>
> >>>
> >>
> >> --
> >> Don Murray
> >> NOAA/ESRL/PSD and CU-CIRES
> >> 303-497-3596
> >> http://www.esrl.noaa.gov/psd/people/don.murray/
> >>
> >>
> >
> > Ticket Details
> > ===================
> > Ticket ID: RIZ-451320
> > Department: Support netCDF Java
> > Priority: Normal
> > Status: Open
> >
> 
> --
> Don Murray
> NOAA/ESRL/PSD and CU-CIRES
> 303-497-3596
> http://www.esrl.noaa.gov/psd/people/don.murray/
> 
> 

Ticket Details
===================
Ticket ID: RIZ-451320
Department: Support netCDF Java
Priority: Urgent
Status: Closed