[ncl-talk] Fwd: Another dimensions problem

[Barry Lynn]

Dennis:

Are you saying that I should modify my "feed_data.ncl" program?

I was able to verify that the substitution works and was able to use the
new wrfinput_d0... file for purposes of data assimilation.

Barry

On Wed, Feb 1, 2017 at 8:27 PM, Dennis Shea <shea at ucar.edu> wrote:

> 'For convenience', primarily graphical convenience, NCL allows
> multidimensional attributes to be associated with variables. However, the
> underlying netCDF software precludes writing multi-dimensional attributes.
> Multidimensional attributes are written as 1D.
>
> As a side point: netCDF and NCL do not allow cascading attributes:
> attributes can not have  attributes.
>
> See:
> http://www.unidata.ucar.edu/software/netcdf/netcdf/Differences-between-
> Attributes-and-Variables.html
>
> ---
> Again, 'for convenience', NCL high level graphical interfaces are aware of
> specific multi-dimensional attributes (eg: 'lat2d', 'lon2d' ). However, if
> variables X, Y, Z each has associated with it the lat2d, lon2d attributes
> for graphical reasons  and, subsequently, each variable is written to a
> netCDF file, the file will have these attributes written for each variable.
> If the lat2d & lon2d arrays are large, this could have a significant impact
> on file size.
>
> IMHO: when writing netCDF
>
> [1]
> Write the lat2d, lon2d as separate variables. Any name: LAT, LON, LAT2D,
> LON2D, XLAT, XLONG,.....).
>
> [2]
> Not required, but recommended, associate with each variable being written
> a 'coordinates' attribute specifying the variables containing coordinates
> (separated by spaces), say
>
>      X at coordinates = "XLONG XLAT"
>      Y at coordinates = "XLONG XLAT"
>
> [3]
> Delete the 'lat2d' and 'lon2d'  attributes *PRIOR* to writing the
> variables to the file
>       delete([/ X at lat2d, X at lon2d, ....., Z at lat2d, Z at lon2d /])
>
> D
>
>
>
>
>
>
> On Wed, Feb 1, 2017 at 10:03 AM, Alan Brammer <abrammer at albany.edu> wrote:
>
>> There’s something weird going on with how ncl interprets the lat2d and
>> lon2d attributes.
>>
>> If you redefine the attributes in the script as you had commented out.
>> e.g.
>> l_obs at lat2d :=  xlat(0,:,:)       ; this is for plotting
>> l_obs at lon2d := xlon(0,:,:)     ; using gsn_csm routines
>>
>> When they get written to netcdf they are converted to actual 1d arrays.
>> While they’re in the script they are in a weird world of being a fake 2d
>> array.
>>
>> I’m surprised that NCL doesn’t handle a 1d array and unwrap it
>> accordingly though.
>>
>>
>> Good luck.
>>
>>
>>
>>
>> On 1 Feb 2017, at 11:17, Barry Lynn <barry.h.lynn at gmail.com> wrote:
>>
>> I hope someone might have a suggestion.  Thank you.
>> ---------- Forwarded message ----------
>> From: Barry Lynn <barry.h.lynn at gmail.com>
>> Date: Sun, Jan 29, 2017 at 2:36 PM
>> Subject: Another dimensions problem
>> To: ncl-talk <ncl-talk at ucar.edu>
>>
>>
>> Hi:
>>
>> I cannot succeed to map a variable from the wrfinput_d02.nc file.
>>
>> I get a dimension problem (different dimensions, different sizes).
>>
>> This problem seems to happen often and using (/var/) didn't solve it.
>>
>> Thank you,
>>
>> Barry​
>>  wrfinput_d02.nc
>> <https://drive.google.com/file/d/0B3E3GjUeKpBdUXBVdk5VeW95WUk/view?usp=drive_web>
>> ​
>>
>> --
>> Barry H. Lynn, Ph.D
>> Senior Lecturer,
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <(914)%20432-3108>
>>
>>
>>
>> --
>> Barry H. Lynn, Ph.D
>> Senior Lecturer,
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <(914)%20432-3108>
>> <l_obs_map.ncl><map_output.file>____________________________
>> ___________________
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>


-- 
Barry H. Lynn, Ph.D
Senior Lecturer,
The Institute of the Earth Science,
The Hebrew University of Jerusalem,
Givat Ram, Jerusalem 91904, Israel
Tel: 972 547 231 170
Fax: (972)-25662581

C.E.O, Weather It Is, LTD
Weather and Climate Focus
http://weather-it-is.com
Jerusalem, Israel
Local: 02 930 9525
Cell: 054 7 231 170
Int-IS: x972 2 930 9525
US 914 432 3108
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