[gradsusr] Pass Data via the 'Return' Expression
Mark Sponsler
msponsler at comcast.net
Fri Apr 23 11:39:19 EDT 2010
Brian,
Excellent addtional examples. I am using gfsallow right now, and it works fine if the 'b' script is in the same directory as the 'a' script.
But now I'm kinda stuck because I want the b script to be in a different directory. I'm trying to set up a bunch of common scripts in a standalone directory, so they can be accessed from any grads script elswhere on the drive. So pathing is now the issue.
I'm trying to locate 'script b' using gfspath.
Say 'script a' is here: c:/grib/a (and executed from that location), and 'script b' (the .gsf script) is here: c:/grib/b
I can't seem to figure out how to get gfspath to go 'up' one directory, then down into directory b
I tried
rc = gsfpath("./b") but the scripts hangs on the gfspath command.
I'm on a Windows build of Grads.
Thanks,
Mark
----- Original Message -----
From: "Brian Doty" <doty at cola.iges.org>
To: "GrADS Users Forum" <gradsusr at gradsusr.org>
Sent: Thursday, April 22, 2010 7:42:56 PM GMT -08:00 US/Canada Pacific
Subject: Re: [gradsusr] Pass Data via the 'Return' Expression
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
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> ------------------------------------------------------------------------
>
> _______________________________________________
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>
--
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."
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