[gradsusr] Pass Data via the 'Return' Expression
Brian Doty
doty at cola.iges.org
Thu Apr 22 22:42:56 EDT 2010
The "gsfallow" stuff is usually the better solution, but I will also
note that if you have a main script that issues the run command to
grads, ie:
"run myscript.gs "args
and if that script returns something via the return statement, then
that string is available to the first script in the result variable.
Example:
script a:
"run b.gs testing"
say "--->"result"<---"
script b:
function b(args)
return(subwrd(args,1))
If you run a.gs from within grads, you should see the following line
output:
---->testing<----
...Brian
On Apr 21, 2010, at 8:42 PM, Mark Sponsler wrote:
> Charles,
> It works perfectly now. Excellent example you provided. I had
> previous read the tutorial provided, but never really understood the
> implications of it all until I saw your example. It makes perfect
> sense now. Thanks so much for taking the time to help. Would have
> never figured it out on my own.
>
> Thanks again,
> Mark
>
>
> ----- Original Message -----
> From: Charles Seman
> To: GrADS Users Forum
> Sent: Wed, 21 Apr 2010 23:47:00 +0000 (UTC)
> Subject: Re: [gradsusr] Pass Data via the 'Return' Expression
>
> Hi Mark,
>
> Please find attached main.gs (calling script) and add1.gsf (GrADS
> script
> function).
>
> ***********************
> * Main script
> ***********************
>
> rc = gsfallow("on")
>
> iVal = 1
>
> say 'iVal = 'iVal
> say 'Making Call to GrADS script function "add1"'
>
> oVal = add1(iVal)
>
> say 'Call Made - Checking for Answer'
>
> say 'oVal = 'oVal
>
> Try using GrADS main script as follows:
>
> ga-> main.gs
> iVal = 1
> Making Call to GrADS script function "add1"
> input val = 1
> new val = 2
> Passing Variable Back to Main Script
> Call Made - Checking for Answer
> oVal = 2
>
>
> in main.gs, a call is made to an external user-defined script function
> "add1.gsf" (http://grads.iges.org/grads/gadoc/gsf.html) and can be
> called from *outside* of main.gs because of "rc = gsfallow("on")" in
> main.gs and because of the suffix "gsf" for "add1.gsf"...
>
> first, if only the line "rc = gsfallow("on")" is commented out
> (add1.gsf
> exists), the result (you can try this):
> ga-> main.gs
> iVal = 1
> Making Call to GrADS script function "add1"
> Function not found: add1
> Error occurred on line 12
> In file main.gs
>
> next, if the line "rc = gsfallow("on")" is active, but add1.gsf is
> renamed to add1.gs (you can try this):
> ga-> main.gs
> iVal = 1
> Making Call to GrADS script function "add1"
> Function not found: add1
> Error occurred on line 12
> In file main.gs
>
> Hope this helps,
> Chuck
>
> Mark Sponsler wrote:
> >
> > Hi Chales,
> > I took a look at the script you referenced and was similar to others
> > I've seen where the main script and the subscripts are all encased
> in
> > the same physical file. What I'm trying to accomplish is to have a
> > main script in one directory and a bunch of scripts of comomonly
> used
> > routines in a separate directory. The idea is to have the main
> script
> > call one of the common routines, then have the common routine pass
> > some variable data back to the main script for additional
> processing.
> >
> > Below is a simple example with both scripts in the same directory.
> The
> > problem is the value _val1 never gets returned to the main script.
> > I'm using Grads 1.9 on WinXP.
> >
> > Any thoughts or ideas would be welcome!
> >
> > ***********************
> > * Main script
> > ***********************
> >
> > rc = gsfallow("on")
> >
> > val = 1
> >
> > say 'Val = 'val
> > say 'Making Call to Test_Call'
> >
> > 'run test_call.gs 1'
> >
> > say 'Call Made - Checking for Answer'
> >
> > say 'New val = '_val1
> >
> >
> > Here's the called script
> > ************************
> > * Seconadry Script
> > ************************
> > function main (args)
> > if (args='')
> > say 'No argument provided. Argument must be a value 1-10'
> > return
> > else
> > val = subwrd(args,1)
> > endif
> >
> > say 'Val = 'val
> >
> > _val1 = (val + 1)
> >
> > say 'New Val = '_val1
> >
> > say 'Passing Variable Back to Main Script'
> >
> > return(_val1)
> >
> > Thanks,
> > Mark
> >
> >
> > ----- Original Message -----
> > From: Charles Seman
> > To: GrADS Users Forum
> > Sent: Tue, 20 Apr 2010 21:21:12 +0000 (UTC)
> > Subject: Re: [gradsusr] Pass Data via the 'Return' Expression
> >
> > 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
> > >
> > >
> ------------------------------------------------------------------------
> > >
> > > _______________________________________________
> > > gradsusr mailing list
> > > 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,
> > the United States Department of Commerce, or NOAA."
> >
> > _______________________________________________
> > gradsusr mailing list
> > gradsusr at gradsusr.org
> > http://gradsusr.org/mailman/listinfo/gradsusr
> >
> ------------------------------------------------------------------------
> >
> > _______________________________________________
> > gradsusr mailing list
> > 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,
> the United States Department of Commerce, or NOAA."
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
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