| Re: Static Variables in IDL [message #5901] |
Thu, 14 March 1996 00:00 |
steinhh
Messages: 260
Registered: June 1994
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Senior Member |
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In article <4i7ara$606@vixen.cso.uiuc.edu>, santanu@ux7.cso.uiuc.edu (Santanu Bhattacharyya) writes:
|>
|> Hi,
|> Is there a way to statically allocate variables in IDL ? I would
|> like to define a static variable in a .pro which is repeatedly called
|> from an upper level. I am specifically looking for the IDL counterpart
|> of
|> static int testint;
|>
|> I would appreciate any help in this regard,
The IDL counterpart is to put the variable in a common block:
pro test
common test_static,testint
if N_elements(testint) eq 0 then testint = <init_value>
;; Use your testint variable for anything.
;; It keeps it's value between each call
end
Stein Vidar
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| Re: Static Variables in IDL [message #5903 is a reply to message #5901] |
Thu, 14 March 1996 00:00  |
David Foster
Messages: 341
Registered: January 1996
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Senior Member |
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santanu@ux7.cso.uiuc.edu (Santanu Bhattacharyya) wrote:
>
> Hi,
> Is there a way to statically allocate variables in IDL ? I would
> like to define a static variable in a .pro which is repeatedly called
> from an upper level.
As much as I hate to use COMMON blocks unless I absolutely have to,
this would be one way of doing this. Another way would be to use
handles (HANDLE_VALUE(), HANDLE_CREATE(), etc.).
"Static" would be a great new reserved word for the next IDL version.
Dave Foster
UCSD Brain Image Analysis Lab
foster@bial1.ucsd.edu
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| Re: Static Variables in IDL [message #5904 is a reply to message #5901] |
Thu, 14 March 1996 00:00 |
steinhh
Messages: 260
Registered: June 1994
|
Senior Member |
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In article <4i8geg$5fv@vixen.cso.uiuc.edu>, santanu@eehpx22.cen.uiuc.edu (S Bhattacharyya) writes:
|>
|>
|> Pardon me if I appear a bit obtuse, but I am still a little confused. I am
|> under the impression that the common block declaration is equivalent to
|> C's global declaration. What I would like to have is a bit of non re-entrant
|> code in a standalone function (.pro). I want an IDL .pro that does the
|> following::
|>
|> main()
|> {
|> for(;;) non_rEntrant();
|> }
|> non_rEntrant()
|> {
|> static int block=1;
|>
|> if (block == 1){
|> puts("This is executed only once");
|> block=0;
|> }
|> puts("And this is done over and over again");
|> }
pro main
while 1 do non_rEntrant
end
pro non_rEntrant
common non_rEntrant_private_others_keep_off,block
if N_elements(block) eq 0 then block=1 ;; Instead of "static .... =1"
if block eq 1 then begin
print,"This is executed only once"
block = 0
end
print,"And this is done over and over again"
end
This will do what you want. Common blocks are not quite like
global declarations. I can have e.g., a variable called block
in the main program without having a conflict. I can even
have a variable called block at the interactive prompt level,
and still have no conflict.
|> call_procedure,'non_rEntrant'
You'll get speedier programs by using just
non_rEntrant
as in the example above 8-)
Stein Vidar
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| Re: Static Variables in IDL [message #5913 is a reply to message #5901] |
Wed, 13 March 1996 00:00 |
rivers
Messages: 228
Registered: March 1991
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Senior Member |
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In article <4i7ara$606@vixen.cso.uiuc.edu>, santanu@ux7.cso.uiuc.edu (Santanu Bhattacharyya) writes:
> Hi,
> Is there a way to statically allocate variables in IDL ? I would
> like to define a static variable in a .pro which is repeatedly called
> from an upper level. I am specifically looking for the IDL counterpart
> of
> static int testint;
>
Yes, it is easy. Use a common block. Make the name of the common block unique
enough that you can be sure it won't conflict with common blocks used in other
procedures.
common unique_name, testint
testint = 14
testint will have the value 14 the next time the .pro file is called.
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CARS (312) 702-9951 (secretary)
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