Re: scope of variable in NCL

Hi Saji,
Wei is quite correct about this case. Arguments are passed by
reference and the variables they reference can be modified inside the
function. The 'local' statement has no meaning for arguments. You can
ignore the last message I sent. I apologize that I did not notice that
'a' was being used as an argument to the function.
  -dave

On Oct 16, 2009, at 8:09 AM, Wei Huang wrote:

> Saji,
>
> That is because you use "a" as an argument element, and local.
>
> If you do "print("" + test(0,1,2))", then you can not change "a"
> out side your function.
>
> Wei Huang
> huangwei@ucar.edu
> VETS/CISL
> National Center for Atmospheric Research
> P.O. Box 3000 (1850 Table Mesa Dr.)
> Boulder, CO 80307-3000 USA
> (303) 497-8924
>
>
>
>
>
> On Oct 15, 2009, at 11:03 PM, Saji N Hameed wrote:
>
>> Even declaring "a" as local does not seem to work :(
>> ncl 1> function test(a,b,c)
>> ncl 2> local a,b,c
>> ncl 3> begin
>> ncl 4> a=-999
>> ncl 5> return(1)
>> ncl 6> end
>> ncl 7> print(""+test(a,1,2))
>> (0) 1
>> ncl 8> print(""+a)
>> (0) -999
>>
>> * Saji N Hameed <saji@apcc21.net> [2009-10-16 13:59:15 +0900]:
>>
>>> Dear NCL Developers,
>>>
>>> I suppose that the following should not happen. Isn't it a bug?
>>> We are told that variables inside a function have local scope, and
>>> this unusual feature can lead to a lot of headaches. Any solutions,
>>> other than "local a" or using another variable name than "a"
>>>
>>> Copyright (C) 1995-2009 - All Rights Reserved
>>> University Corporation for Atmospheric Research
>>> NCAR Command Language Version 5.1.1
>>> The use of this software is governed by a License Agreement.
>>> See http://www.ncl.ucar.edu/ for more details.
>>> ncl 0> a=5
>>> ncl 1> function testme(a,b,c)
>>> ncl 2> begin
>>> ncl 3> a=2
>>> ncl 4> return(1)
>>> ncl 5> end
>>> ncl 6> print(""+a)
>>> (0) 5
>>> ncl 7> print(""+testme(a,1,2))
>>> (0) 1
>>> ncl 8> print(""+a)
>>> (0) 2
>>>
>>> Thanks,
>>> saji
>>> --
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
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>>
>> --
>> Saji N. Hameed
>>
>> APEC Climate Center
>> 1463 U-dong, Haeundae-gu, +82 51 745
>> 3951
>> BUSAN 612-020, KOREA saji@apcc21.net
>> Fax: +82-51-745-3999
>>
>>
>>
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Received on Fri Oct 16 09:29:40 2009