[gradsusr] Pass Data via the 'Return' Expression

[Brian Doty]

Here's a function I use to format the grads date and time for various  
plot annotation (titles, etc):

*  Function to reformat the GrADS date/time into something
*  more readable

function mydate
   'query time'
   sres = subwrd(result,3)
   wd = subwrd(result,6)
   i = 1
   while (substr(sres,i,1)!='Z')
     i = i + 1
   endwhile
   hour = substr(sres,1,i)
   isav = i
   i = i + 1
   while (substr(sres,i,1)>='0' & substr(sres,i,1)<='9')
     i = i + 1
   endwhile
   day = substr(sres,isav+1,i-isav-1)
   month = substr(sres,i,3)
   year = substr(sres,i+3,4)
   return (hour' 'wd', 'month' 'day', 'year)

As you can see, it returns some stuff there at the end.

When you invoke this function from elsewhere, there are a couple of  
ways to use the returned string.  One way is to assign it to a variable:

dtlabel = mydate()

Another way is to just use it inline, for example:

'draw string 0.1 0.2 12Hr Forecast Valid 'mydate()

There is also a way to share variables between script functions by  
using a "global" variable, which is any variable name that starts with  
an underscore.  Those variables are shared by all the functions in the  
script file.  I tend to avoid using them (because it can be hard later  
to figure out where they are getting set vs where they are getting  
used) -- but they do come in handy at times... Brian

On Apr 20, 2010, at 5:21 PM, Charles Seman wrote:

> Mark,
>
> Don't know if you have resolved this yet, but Bob Hart's "plotskew.gs"
> script has examples of what it appears that you want to do:
> http://www.iges.org/grads/gadoc/library
> ftp://grads.iges.org/grads/scripts/plotskew.gs
>
> Hope this helps,
> Chuck
>
> Mark Sponsler wrote:
>>
>> I have a script that calls a second script (and passes some arguments
>> to it). That works fine. I'm trying to get the second script to  
>> return
>> some data back to the first script, but am having difficulty.  I use
>> the 'return' command to have the second script return control back  
>> the
>> first script, but cannot seem to get any variable data to pass with
>> it. It seems this is possible per the Grads documentation:
>>
>>
>>
>>
>>
>> To return from a function, use the |return| command:
>>
>>    |return /expression/|
>>
>>    The |/expression/| is optional; if not provided, a NULL string
>>    will be returned. (A null string is: '') The result of the
>>    function is the result of the expression specified on the return
>>    command.
>>
>>
>>
>> In the second script, the last line is:
>>
>>
>>
>> return val1
>>
>>
>>
>> Where val1 is a variable string
>>
>>
>>
>> Just can't seem to get the first script to read the contents of
>> val1. Could always write the data to a file, but am looking for
>> something a little more elegant.
>>
>>
>>
>>
>> Any help would be appreciated,
>> Mark
>>
>> ------------------------------------------------------------------------
>>
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>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>
> -- 
>
> Please note that Charles.Seman at noaa.gov should be considered my NOAA
> email address, not cjs at gfdl.noaa.gov.
>
> ********************************************************************
> Charles Seman                                Charles.Seman at noaa.gov
> U.S. Department of Commerce / NOAA / OAR
> Geophysical Fluid Dynamics Laboratory         voice: (609) 452-6547
> 201 Forrestal Road                              fax: (609) 987-5063
> Princeton, NJ  08540-6649            http://www.gfdl.noaa.gov/~cjs/
> ********************************************************************
>
> "The contents of this message are mine personally and do not reflect  
> any
> official or unofficial position of the United States Federal  
> Government,
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