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From: khb@chiba.Eng.Sun.COM (Keith Bierman - SPD Advanced Languages)
Newsgroups: comp.lang.fortran
Subject: Re: Dimensioning arrays at run-time, best way?
Message-ID: <KHB.90Sep18101100@chiba.Eng.Sun.COM>
Date: 18 Sep 90 17:11:00 GMT
References: <1990Sep18.115704.20642@msuinfo.cl.msu.edu>
Sender: news@exodus.Eng.Sun.COM
Organization: Sun MegaSystems
Lines: 55
In-reply-to: fox@DASHER.NSCL.MSU.EDU's message of 18 Sep 90 12:53:24 GMT


In article <1990Sep18.115704.20642@msuinfo.cl.msu.edu> fox@DASHER.NSCL.MSU.EDU writes:

   In article <1990Sep17.150155.10220@alchemy.chem.utoronto.ca>, mroussel@alchemy.chem.utoronto.ca (Marc Roussel) writes...

   > 
   >Let your PROGRAM block be a dummy.  (I.E. don't put any code into it
   >that does anything but set N (the array size) and calls a subroutine
   >which does the real work.)  Then call your subroutine.  Most FORTRAN
   >compilers don't check for the right number of parameters in a subroutine
   >call, so the following may not be portable, but it should do the work on
   >most computers.

I have often done well the "other way around" instead of

   > 
   >      PROGRAM EXAMPLE
   >      read(*,*)n
   >      call sub1(n)
   >      END
   > 
   >      SUBROUTINE SUB1(N,X)
   >      real X(N)
.....
   >      END


	program example

	print*,"how many bytes ?"
	read(*,*) nbytes
	x=malloc(nbytes)
	call realprog(x,nbytes/4)
	end
	subroutine realprog(x,n)
c
c	this is where the "real program" begins
c	
	real x(n)

c	do processing, including all calls
c
	return	
	end

The "spelling" of how to procure the memory varies, malloc works on
Sun and most unix boxes; I forget which sys$ call does the trick on
VMS, and etc. but it is usually easy to find. Only a few lines in the
formal main program need to adjusted from system to system.

--
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Keith H. Bierman    kbierman@Eng.Sun.COM | khb@chiba.Eng.Sun.COM
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