[ncl-talk] Array initialization question

[Dave Allured - NOAA Affiliate]

Oops, I missed a simpler approach which is fine when your returned arrays
do not need any custom attached attributes.

function data_read(rfile[1]:string)
  begin
    x = True    ; simple container variable
    recon_data := asciiread(rfile,-1,"string")
    x at lat = stringtofloat(str_get_cols(recon_data, 9,15))
    x at lon = stringtofloat(str_get_cols(recon_data, 23,29))
    return (x)
  end

Main script:

  rdat = data_read(file)
  printVarSummary (rdat at lat)
  printVarSummary (rdat at lon)

--Dave A.


On Mon, Jul 2, 2018 at 2:57 PM, Dave Allured - NOAA Affiliate <
dave.allured at noaa.gov> wrote:

> Dave V,
>
> Here is one possible approach which I have used in similar applications.
>
> function data_read(rfile[1]:string,var[1]:string)
>   begin
>     recon_data := asciiread(rfile,-1,"string")
>     if (var .eq. "lat") then
>       return (stringtofloat(str_get_cols(recon_data, 9,15)))
>     end if
>     if (var .eq. "lon") then
>       return (stringtofloat(str_get_cols(recon_data, 23,29)))
>     end if
>     ; optional handling here for "unknown variable name"
>   end
>
> Main script:
>
>   lat = data_read(file,"lat")
>   lon = data_read(file,"lon")
>
> This might seem klunky, but it avoids predefinition tricks and is fairly
> simple, given the constraints of NCL procedure calling.
>
> --Dave
>
>
> On Mon, Jul 2, 2018 at 2:10 PM, Vollaro, David <dvollaro at albany.edu>
> wrote:
>
>> Hi,
>>
>>
>> I have created a procedure to read an ASCII dataset.  The procedure will
>> fill several 1D variable arrays and pass them back to the main NCL script.
>> My problem is that the call statement contains several variables that have
>> not been previously defined.  The length of these arrays will be determined
>> in the procedure and is dataset dependent.  Is there a way to predefine a
>> variable array w/o knowing its size?  Attached is a snippet of code:
>>
>>
>> Dave Vollaro
>>
>> ...
>>
>> main script...
>>
>>
>> data_read(file,lat,lon)
>>
>> ....
>>
>>  procedure data_read(rfile:string,rlat[*]:float,rlon[*]:float)
>>  begin
>>
>>   recon_data   := asciiread(rfile,-1,"string")
>>   rlat = stringtofloat(str_get_cols(recon_data, 9,15))
>>   rlon = stringtofloat(str_get_cols(recon_data, 23,29))
>>   return
>>
>>  end
>> fatal:Variable (lat) is undefined
>>
>
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