I'm not sure if this is what you're looking for, NEC ported to C:

http://5b4az.chronos.org.uk/pages/nec2.html

73, de Nate

--

"The optimist proclaims that we live in the best of all possible worlds,
the pessimist fears this is true."

Good news!

It is really possible, to speed up NEC calculations with CPUs
containing more then one core. I will try to implement a wrapper-
executable, that makes possible with your old NEC-engines (e.g. NEC2).
It need no recompilation of nec engine or any modifications. Just
renaming the old engine and putting the wrapper-engine on the same
directory with the original nec engine file name.

After implementing a new antenna optimizer (that one uses also multi-
core, multi-cpu enhancement), I will start with the wrapper code. I
will test the code with 4nec2, so many of you could take advantage of
multi-cores with 4nec2.

regards,
Aziz

On Sep 25, 5:12 am, Nate Bargmann
wrote:
I'm not sure if this is what you're looking for, NEC ported to C:


Hmmm.. Isn't that the version that used f2c to convert the FORTRAN to
C? Probably a bad plan overall.. there's some reputed bugs in the
process, and it's going to use different libraries, etc. If you're
worried about performance, stick with the FORTRAN and use a good
compiler.

On Sep 30, 3:35 pm, wrote:
Good news!

It is really possible, to speed up NEC calculations with CPUs
containing more then one core. I will try to implement a wrapper-
executable, that makes possible with your old NEC-engines (e.g. NEC2).
It need no recompilation of nec engine or any modifications. Just
renaming the old engine and putting the wrapper-engine on the same
directory with the original nec engine file name.

After implementing a new antenna optimizer (that one uses also multi-
core, multi-cpu enhancement), I will start with the wrapper code. I
will test the code with 4nec2, so many of you could take advantage of
multi-cores with 4nec2.

regards,
Aziz

An excellent idea. Arie has already put a decent symbol substitution
processor in, so if you can read the same files, and then farm out the
various symbol values to the processors in a reasonable way, that
would be pretty useful.

Hello Jim,

on the last 6 month, I wrote a "C-language-like" NEC-Compiler, which
generates symbolic antenna models and therefore the output model can
be read directly from 4nec2. The generated code is fully symbolic, so
the antenne parameters can be optimized with 4nec2 as usual.

As an experiment of one of the simplest optimization function (monte
carlo method), I started the new optimizer and of course in the hope
of getting some speed enhancements. Some antenne problems have a big
local minima problem and sometimes the optimization get stucks in a
next optimum level (local minima), but not the best one (global
minima).

With the monte carlo method, this can not be happend, but it takes
much more computation time. The new optimizer of course, uses the new
NEC-compiler, to generate different parameters and NEC-Input for the
engines.

At the moment, I interrupted the development of the optimizer and
startet with the NEC-Engine Wrapper. I have coded during last night
the most parts of it and I just have to merge the results now. On my
dual-core Intel CPU, the performance level of the CPU goes directly to
100% with running two NEC-Engines in the background, so they use all
the CPU-Cores at the same time.
Merging the results, is much more non-trivial part. I hope, I can
solve this very elegant.
The integration of the NEC-Wrapper will be transparent and seamless.

I will see, how far I can go.

Regards,
Aziz

On 1 Okt., 06:01, wrote:
On Sep 30, 3:35 pm, wrote:





Good news!

It is really possible, to speed up NEC calculations with CPUs
containing more then one core. I will try to implement a wrapper-
executable, that makes possible with your old NEC-engines (e.g. NEC2).
It need no recompilation of nec engine or any modifications. Just
renaming the old engine and putting the wrapper-engine on the same
directory with the original nec engine file name.

After implementing a new antenna optimizer (that one uses also multi-
core, multi-cpu enhancement), I will start with the wrapper code. I
will test the code with 4nec2, so many of you could take advantage of
multi-cores with 4nec2.

regards,
Aziz

An excellent idea. Arie has already put a decent symbol substitution
processor in, so if you can read the same files, and then farm out the
various symbol values to the processors in a reasonable way, that
would be pretty useful.- Zitierten Text ausblenden -

- Zitierten Text anzeigen -

I forgot to mention, that the nec code is compatible with 4nec2-files.
I am also able to compile the 4nec2 symbolic code. And the compiled
output is also compatible to 4nec2.

IT IS INCREDIBLE!
My beta NEC-Booster is WORKING now!

I implemented the Frequency Sweep (FR-Cards 1) optimization. For
more then one Frequency, the multi-processor / multi-core enhancement
of my PC is fully occupied. On my dual-core Pentium, the calculation
time decreases almost to half of normal NEC2 calculation time.

I will do now the Radiation Pattern optimization. Especially, if
somebody only have one Frequency defined. This part is a non-trivial
part and takes some more implementation time.

I need some people as a beta-tester. So I can fix all bugs and special
cases.
I will let you know, when I am finished.
Aziz

Update:

Now implemented also Radiation-Pattern-Division. It is working.

On most antenna calculations, there will be speed enhancements on
multi-core / multi-processor systems with original windows-based NEC2
engines. But not for all antennas. It depends on many factors.

I achieved a seamless integration with fall backs, if there is no
optimization possible. The generated (merged) output will be 100%
compatible.

State now: Testing beta-version.
Coming State: Documentation and making on the web free (for private
use) for download.

I hope, at the lastest one week there will be a first relase for
download.

Regards,
Aziz