[Trilinos-Users] az_reorder.f

[Mike Heroux]

Simone,

It was a common practice, and probably still is in some circles, to declare
an array this way, even if the array had more than one element.  It is a
simple way to tell the compiler that the argument was an array without
needing to declare its dimension.  Since Fortran compilers by default did
not (do not?) check the array bounds, there was no practical difference
between this type of declaration and a more rigorous specification.

If you are compiling with array bounds checking on, then the runtime library
will complain, but it is very likely not a real error, especially since this
code is very mature and has not been changes in many years.

Mike

> -----Original Message-----
> From: trilinos-users-bounces at software.sandia.gov 
> [mailto:trilinos-users-bounces at software.sandia.gov] On Behalf 
> Of Simone Deparis
> Sent: Sunday, December 04, 2005 10:37 PM
> To: trilinos-users at software.sandia.gov
> Subject: [Trilinos-Users] az_reorder.f
> 
> Hi,
> 
> I have the following question, probably a dummy one because I 
> am not used to fortran notation:
> 
> in packages/aztecoo/src/az_reorder.f:184
> we call
> jstrt    = xadj(node)
> jstop    = xadj(node + 1) - 1
> 
> (with,  node=1 in my case),
> where xadj is decleared as a
> integer xadj(1)
> I do not understand why we can access xadj(2) Is this correct?
> 
> Thank you
> Simone
> PS: I encounter a
> Subscript out of range on file line 185, procedure 
> ../../../../packages/aztecoo/src/az_reorder
> Attempt to access the 2-th element of variable xadj.
> 
> when Epetra is compiled with bounds checking. I need to 
> discover wheter this comes from my matrix or this piece of code.
> 
> --
> _____________________________________________________________________
>                                      Simone Deparis
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> 
> 
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