Re: NEC-LIST: Fortran execution speed

The ports of nec-2 to C and C++ both use dynamic memory allocation and so have
no built-in limit on segment number (OK, on nec2++ it is 4 billion segments).
The latest (in CVS) version of nec2++ uses LAPACK for it's LU decomposition.
nec2++ is available as part of Debian and Ubuntu and compiles on MacOS and
Windows.

Hope this helps.

Tim Molteno

On Mon, 14 Jul 2008, Darryl Holder wrote:
> I would like to echo the comments of wadavis on his post about the
> execution methods of NEC under Windows. I had a program where I needed
> to model many thousands of segments. I used GNEC (a very good
> commercial version of NEC-4) under Widows XP. Due to the memory
> allocation limits that wadavis mentioned, my models failed at about
> 12,000 segments.
>
> I abandoned that platform and compiled the NEC-4 code from source using
> g77 on a Macintosh running the MacOS X (Unix-based) system. Using the
>
> resources posted on this list by John B. Wood 03/04/04:
> At that time I used both of the above proceedures to compile NEC-4 on
> Mac OS X and got good results for double-precision models of about
> 16,000 wire segments. Later, I recompiled for 30,000 segments and got
> what seemed to be good results for my model.
>
> In my opinion, unless you absolutely must use Windows (especially for
> large models) a good version of Linux or MacOS X probably would be a
> better choice of platform. I do not know if the "Cygwin" environment
> mentioned by john.kot has avoided the Windows memory-limit factor. If
> anyone knows this, it would beneficial.
>
> Hope this helps.

-- 
-------------------------
Dr T.C.A. Molteno
Department of Physics
University of Otago
Box 56, Dunedin
New Zealand
+64-3-479-7752

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