[ncl-talk] urgent issue about reading time series in each subarea of a shapefile

[Amal Inge]

Oh thanks a lot! This is what I want to do!
my script was a mess, many thanks for your help :)

All the best

Le ven. 30 nov. 2018 à 02:15, Mary Haley <haley at ucar.edu> a écrit :

>
> It is still not quite clear to me what you are trying to do.
>
> For example, why is the variable being called "pmask" on the file? The
> original variable name is "dox", and I see that you also used "oxygen", so
> wouldn't one of these be a better variable name?
>
> You don't need a do loop in order to mask all the data across time steps.
> Instead, create the 2D mask, and then you can apply this mask across your
> 4D dox variable using "conform_dims" to convert your 2D mask variable to a
> 4D mask variable:
>
>    pmask2d    = shapefile_mask_data(dox(0,0,:,:),shp_fname,opt)
>
>    pmask4d    = conform_dims(dox_dims,pmask2d,(/2,3/))
>    dox_masked = mask(dox,pmask4d,1)
>
> You could also create pmask4d with one line, but it's not as readable:
>
>    pmask4d = conform_dims(dox_dims,
> shapefile_mask_data(dox(0,0,:,:),shp_fname,opt),(/2,3/))
>
>    dox_masked = mask(dox,pmask4d,1)
>
> The dox_masked variable is now a 4D variable that you can write to a file.
> No looping required.  See attached script.
>
> --Mary
>
>
> On Thu, Nov 29, 2018 at 11:18 AM Amal Inge <amalingenieur89 at gmail.com>
> wrote:
>
>> Thank you so much Prof!!You understood me perfectly!
>>
>> Last question, i made the loop just to add the time steps to the 2D mask
>> and after i will concatenate them to have one nc file for all the time
>> steps.
>> Is there another way to have directly ncfile without passing by the loop
>> and having ncfile for each time step?
>> (this morning i made this ncfile attached but i didn't succeed to have
>> the ncfile 4D)
>>
>> thanks again
>> best regards
>>
>> Le jeu. 29 nov. 2018 à 18:10, Mary Haley <haley at ucar.edu> a écrit :
>>
>>> In the future, it would help if you tell us what you mean by the files
>>> being wrong.  I had to run your script and look at different variables in
>>> order to determine what exactly was wrong.
>>>
>>> It looks your "pmask" variable is all missing in each of the output
>>> files.
>>>
>>> It gets calculated correctly with these lines:
>>>
>>> ;---Create masked data array
>>>
>>>    pmask = where(oxygen.eq.1,f,f at _FillValue)
>>>    copy_VarMeta(f,pmask)
>>>
>>> But then later, before "pmask" is written to a NetCDF file, it is reset
>>> to a 4D array with missing values with this line:
>>>
>>>  pmask=new((/1,1,nlat,nlon/), float)
>>>
>>> pmask is never repopulated with values, and hence when it is written to
>>> the file it is all missing.
>>>
>>> I think what you meant to do was convert pmask to a 4D array, where time
>>> and depth each have one dimension, and then copy the 2D pmask to this new
>>> 4D pmask array, correct?
>>>
>>> If so, then instead of the "new" command, you should create a new
>>> variable, say "pmask4d", as follows:
>>>
>>>  pmask4d = reshape(pmask,(/1,1,nlat,nlon/))
>>>  copy_VarAtts(pmask,pmask4d)    ; IMPORTANT, YOU MAY WANT TO ADJUST SOME
>>>                                 ; ATTRIBUTES BEFORE WRITING TO FILE
>>>   pmask4d!0         = "time"
>>>   pmask4d!1         = "depth"
>>>   pmask4d!2         = "latitude"
>>>   pmask4d!3         = "longitude"
>>>   pmask4d&time      = time
>>>   pmask4d&depth     = lev
>>>   pmask4d&latitude  = lat
>>>   pmask4d&longitude = lon
>>>
>>> and then change "pmask" to "pmask4d" in all the code that follows that
>>> writes stuff to the file. For example:
>>>
>>>    filevardef(fout, "pmask"    ,typeof(pmask4d)  ,getvardims(pmask4d))
>>>
>>>    filevarattdef(fout,"pmask",pmask4d)
>>>
>>>    fout->pmask      = (/pmask4d/)
>>>
>>> I've attached a modified version of your script.
>>>
>>> --Mary
>>>
>>>
>>> On Thu, Nov 29, 2018 at 5:39 AM Amal Inge <amalingenieur89 at gmail.com>
>>> wrote:
>>>
>>>> i want to have a time series from an ncfile (bbio.nc attached) for
>>>> each subarea of a shapefilen(pic and zip attached)
>>>> i tried the script attached newtest.ncl to do the mask and produce
>>>> ncfile output for each time step
>>>> but i get  wrong ncfiles
>>>> could you help please?
>>>>
>>>>
>>>>  bbio.nc
>>>> <https://drive.google.com/file/d/1B0Y5bU6_hMcdYROmP4p-BJoGHUxo9FDH/view?usp=drive_web>
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>>>
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