vemsa3d 1.1 - a floss visual em simulator for 3d antennas
p...@grnet.gr
source
158 KB
VEMSA3D_source_11.zip
http://rga.googlecode.com/files/VEMSA3D_source_11.zip
exe standalone
971 KB
VEMSA3D_exe_standalone_11.zip
http://rga.googlecode.com/files/VEMSA3D_exe_standalone_11.zip
vemsa3d all downloads:
http://code.google.com/p/rga/downloads/list
A FLOSS Visual EM Simulator for 3D Antennas
http://arxiv.org/abs/1006.0031
The RGA project:
http://code.google.com/p/rga/
Antennas Research Group, Palaia Morsini, Xanthi, Thrace, Hellas, EU
-Not-for-Profit-
-
Bill Miller
<p...@grnet.gr> wrote in message news:i405hi$vvf$1...@news.grnet.gr...
analysis?
Bill Miller
p...@grnet.gr
| Newsgroups: sci.physics.electromag
| Sent......: Wednesday, August 18, 2010 10:44 PM
| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator for 3d antennas| ...
|>
| How does this work differ from NEC Numeric Electromagnetic Code for antenna
| analysis?
|
| Bill Miller
Dear Mr. Miller,
VEMSA3D can not work differently, because it is based
on the same theoretical method as NEC does, that is on
the Method of Moments.
However, since each of these numerical applications use
a different basis of the current function space and since
their corresponding computer programs use unavoidably
finite linear combinations of them, in general, they
produce different results.
To be specific, the two bases details are included in the
following:
VEMSA3D current basis:
J. H. Rischmond, Radiation and Scattering by Thin-Wire
Structues in the Complex Freqeuncy Domain, (15), p.6
http://tinyurl.com/24zwycy
NEC current basis:
G. J. Burke, A. G. Poggio
Numerical Electromagnetics Code - Method of Moments
Equation (20), p. 11
http://www.si-list.net/NEC_Archives/nec2prt1.pdf
Regards,
Petros Zimourtopoulos
Bill Miller
<p...@grnet.gr> wrote in message news:i4jpqt$14e$1...@speranza.aioe.org...
>| From......: "Bill Miller" <kt...@yahoo.com>
> | Newsgroups: sci.physics.electromag
> | Sent......: Wednesday, August 18, 2010 10:44 PM
> | Subject...: Re: vemsa3d 1.1 - a floss visual em simulator for 3d
> antennas
> |
> | <p...@grnet.gr> wrote in message news:i405hi$vvf$1...@news.grnet.gr...
> |> -
> | ...
> |>
> | How does this work differ from NEC Numeric Electromagnetic Code for
> antenna
> | analysis?
> |
> | Bill Miller
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
> Dear Mr. Miller,
>
> VEMSA3D can not work differently, because it is based
> on the same theoretical method as NEC does, that is on
> the Method of Moments.
>
> However, since each of these numerical applications use
> a different basis of the current function space and since
> their corresponding computer programs use unavoidably
> finite linear combinations of them, in general, they
> produce different results.
Can you quantify further or explain the nature of thes "different results?"
Are there certain classes of antennas for which VEMSA3D might produce more
accurate results than NEC?
Thanks!
Bill Miller
p...@grnet.gr
| news:8das3m...@mid.individual.net...
|
| <p...@grnet.gr> wrote in message
| news:i4jpqt$14e$1...@speranza.aioe.org...
|>| From......: "Bill Miller" <kt...@yahoo.com>
|>| Newsgroups: sci.physics.electromag
|>| Sent......: Wednesday, August 18, 2010 10:44 PM
|>| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator
|>| for 3d antennas
|>|
|>| <p...@grnet.gr> wrote in message news:i405hi$vvf$1...@news.grnet.gr...
|>|> -
|>| ...
|>|>
|>| How does this work differ from NEC Numeric Electromagnetic
|>| Code for antenna analysis?
|>|
|>| Bill Miller
|> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|>
|> Dear Mr. Miller,
|>
|> VEMSA3D can not work differently, because it is based
|> on the same theoretical method as NEC does, that is on
|> the Method of Moments.
|>
|> However, since each of these numerical applications use
|> a different basis of the current function space and since
|> their corresponding computer programs use unavoidably
|> finite linear combinations of them, in general, they
|> produce different results.
1
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|
| Can you quantify further or explain the nature of thes
| "different results?"
|
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Well, I can try. These numerically different results are due
to the different coupling -reaction, or impedance- between two
current distributions for which different function -expression,
type, formula, or equation- is used to describe them in each
one of the two applications, VEMSA3D and NEC.
2
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
| Are there certain classes of antennas for which VEMSA3D
| might produce more accurate results than NEC?
|
| Thanks!
|
| Bill Miller
|
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You are welcome!
VEMSA3D is a thin-wire polygonal modeler in "free space".
Therefore, it has to "exactly" predict or justify the
characteristics of any thin-wire antenna. For this class of
antennas VEMSA3D can be certainly compared with NEC. Anyhow,
this comparison can only be indirect: you have to build and
measure the specific thin-wire antenna first and then to
overlay the results of both applications upon the
measurements. But since this kind of knowledge is definitely
a posteriori, you can try a comparison of both applications
for *any* class of antennas. Here, only the advertisement
builds knowledge a priori; but usually this is followed by
a deep disillusionment.
Regards,
Petros Zimourtopoulos
John Smith
I like how everyone ignores the elephant in the room, thought I would
keep quite, sit back and see if anyone noticed the elephant stepping on
their foot--case of numb feet I guess.
So: What about MMANA-GAL. MMANA-GAL is about an exact work-a-like as
you can get to NEC. Is free, has no limitations in software, etc. Are
there any advantages to your program? Accuracy?
Regards,
JS
p...@grnet.gr
| news:i4s8mn$2oh$1...@news.eternal-september.org...
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Hello, again, JS!
For MMANA-GAL, I just took a look at:
http://mmhamsoft.amateur-radio.ca/pages/mmana-gal.php
where you can also read that, according to its developers,
this application is a descendant of MININEC, that is of NEC.
Therefore, there is no need to add nothing more on what already
written in some previous articles of this thread about VEMSA3D
and NEC.
Furthermore, I also just took a look at:
http://dl2kq.de/promm/
where you can read too that its developers clearly exhibit its
license and capabilities limitations. Therefore, there is also
no need to add nothing more on what they already wrote -not to
mention what it is lengthy said about software pattents and usage
restrictions in this tread.
Finally, the accuracy issue is also has been exhausted in
yesterday article:
| Sent......: Sunday, August 22, 2010 9:38 PM
| Newsgroups: sci.physics.electromag,rec.radio.amateur.antenna
| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator for
| 3d antennas
| From......: p...@grnet.gr
so I have also nothing to add.
Well, after all, it seems that we only forgot to mention the
name of that elephant in the room -perhpas because its
advantageous name is /F/L/O/S/S/.
Best regards,
pez
John Smith
>...
> Well, after all, it seems that we only forgot to mention the
> name of that elephant in the room -perhpas because its
> advantageous name is /F/L/O/S/S/.
>
> Best regards,
>
> pez
>
>
Yes, the free, as in free beer is one great advantage, but an advantage
not all will be able to take advantage of. Since MMANA-GAL and EZNEC
have visual interfaces so similar, being able to use one is effectively
being able to immediately use the other. The learning curve into your
interface takes just a bit longer ... but, as you say, the availability
of the source makes it highly desirable to at least one group.
Thanks for the swift reply,
JS
p...@grnet.gr
| On 8/22/2010 11:55 PM, p...@grnet.gr wrote:
|
|> ...
|> Well, after all, it seems that we only forgot to mention the
|> name of that elephant in the room -perhpas because its
|> advantageous name is /F/L/O/S/S/.
|>
|> Best regards,
|>
|> pez
|
| advantage not all will be able to take advantage of. Since
| MMANA-GAL and EZNEC have visual interfaces so similar, being
| able to use one is effectively being able to immediately use
| the other. The learning curve into your interface takes just
| a bit longer ... but, as you say, the availability of the
| source makes it highly desirable to at least one group.
|
| Thanks for the swift reply,
| JS
|
You're very welcome!
But please take into account that our software is not free,
as in free beer or free gratis; is free, as in liberty, in
free speech or free libre*. Therefore, we don't support
license brokers, promote illegal code use or propagandize
software piracy.
Thank you very much for the chances you gave me to clearly
express our group point of view!
Kind regards,
pez
* Gratis versus Libre:
http://en.wikipedia.org/wiki/Gratis_versus_Libre
Bill Miller
<p...@grnet.gr> wrote in message news:i4uivb$2hi$1...@news.grnet.gr...
>antenneX.com's user group.
Antennex.com is, perhaps, the largest and most diverse website devoted
exclusively to antennas and related items. The website has both free (no
charge) and fee (charge for subscription) sections.
The user group is no charge and there are particiapnts from close to 100
countries with skill levels from enthusiastic amateur to world recognized
experts.
Bill
John Smith
> ...
> You're very welcome!
>
> But please take into account that our software is not free,
> as in free beer or free gratis; is free, as in liberty, in
> free speech or free libre*. Therefore, we don't support
> license brokers, promote illegal code use or propagandize
> software piracy.
>
> Thank you very much for the chances you gave me to clearly
> express our group point of view!
>
> Kind regards,
>
> pez
>
> * Gratis versus Libre:
> http://en.wikipedia.org/wiki/Gratis_versus_Libre
Well, as you have seen, a concept such as "free" can mean many things to
many different people, splitting hairs on that is only a waste of time
some can engage in here ... However, I have downloaded the source, in
C++, and have been making notes and stub testing various parts. One
aspect of the source which really strikes me in the face, it is
un-commented! Ya' just gotta luv that software engineer! ROFLOL
Regards,
JS
p...@grnet.gr
NASA does not infinitely support direct linking to its
Technical Reports Server (NTRS) contents. Therefore, the link
given in article:
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| Sent......: Thursday, August 19, 2010 7:32 PM
| Newsgroups: sci.physics.electromag,rec.radio.amateur.antenna
| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator for
| 3d antennas
|
| ...
| J. H. Richmond, Radiation and Scattering by Thin-Wire
| Structures in the Complex Frequency Domain, (15), p.6
| http://tinyurl.com/24zwycy
| ...
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is not a valid one anymore. One has to firstly connect to
NTRS:
http://ntrs.nasa.gov/search.jsp
and search for:
"Radiation and scattering by thin-wire structures in the
complex frequency domain"
or some adequate part of it, e.g. like the following one,
which it seems that currently holds:
"Radiation and scattering by thin-wire"
to get the Richmond's report item first and after two
more steps the full-text through "View PDF File".
Petros Zimourtopoulos
p...@grnet.gr
| many things to many different people, splitting hairs on that
| is only a waste of time some can engage in here ...
| However, I have downloaded the source, in C++, and have been
| making notes and stub testing various parts. One aspect of
| the source which really strikes me in the face, it is
| un-commented! Ya' just gotta luv that software engineer!
| ROFLOL
|
| Regards,
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Dear JS,
Thank you for pointed out this issue too!
As I already said, VEMSA3D is open source code, which is
distributed as free-libre; not free-gratis. Therefore, we
keep the right to publish full-comments about our source
code sometime in the future, as everybody else of course.
Please, see GNU GPL 3.0:
http://www.gnu.org/licenses/gpl.html
Free-gratis is the MS Windows application VEMSA3D, which
*everyone* can enjoy the production of it by simply following
the fully-commented instructions we already gave at the third
page, right column, of our paper:
http://arxiv.org/abs/1006.0031
Best regards,
pez, SV7BAX
p...@grnet.gr
| Newsgroups: rec.radio.amateur.antenna,sci.physics.electromag
| Sent......: Tuesday, August 24, 2010 1:00 AM
| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator
Thank you very much, Bill, I really appreciate your offer.
Please try to do so -if you are an unmoderated user of the
magazine list, of course- since our accounts to magazine
e-list are about to expire, while, after 7 years or so, our
group members' subscriptions to the magazine, have been
recently expired -the last one today:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| Sent...: Tuesday, August 24, 2010 7:03 AM
| Subject: Your antenneX Paid Subscription Account has Expired
| From...: antenneX Online Magazine listmgr-at-antennex.com
| To.....: Petros Zimourtopoulos ...-at-antennas.gr
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Petros
Bill Miller
Petros ...
I posted some information on your VEMSA3D on Antennex's discussion group,
but your email bounced. May I have a correct email for you, please? PM me if
you'd like.
Bill Miller
kt4yeatyahoo.com
John Smith
>> ...
> Dear JS,
>
> Thank you for pointed out this issue too!
>
> As I already said, VEMSA3D is open source code, which is
> distributed as free-libre; not free-gratis. Therefore, we
> keep the right to publish full-comments about our source
> code sometime in the future, as everybody else of course.
> Please, see GNU GPL 3.0:
> http://www.gnu.org/licenses/gpl.html
>
> Free-gratis is the MS Windows application VEMSA3D, which
> *everyone* can enjoy the production of it by simply following
> the fully-commented instructions we already gave at the third
> page, right column, of our paper:
> http://arxiv.org/abs/1006.0031
>
> Best regards,
>
> pez, SV7BAX
>
Again, I would never look a gift horse in the mouth ... I don't find the
lack of comments an surmountable problem. If you have a basic
understanding of the concepts which a piece of software source deals
with, it is relatively easy to locate them and comment/document them
yourself. For example, when looking in software for routines and
statements dealing with a circle, you would simple search for constructs
dealing with area, circumference, diameter, etc. It is just a logical
progression to look for those dealing with the implementation of the
moment method. NEC source used in conjunction with these efforts makes
it a tolerable exercise in reverse engineering the task ...
I see nothing wrong with expecting someone to do a bit of work to get
something for "free", LOL.
Regards,
JS
p...@grnet.gr
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Bill,
Yes, indeed! I just saw your appreciative message for vemsa3d
along with the comments of other [Antenna-discussion] list
members, just a little before, when I unsubscribed from that
list:
-
| Sent...: Wednesday, August 25, 2010 8:43 AM
| Subject: You have been unsubscribed from the Antenna-discussion
| : mailing list
| To.....: ...-at-gmail.com
| From...: antenna-discu...@antennex.com
|
| Thanks for your stay with us!
|
| Regards, Listmgr
-
as well as of that one founded by ever memorable Cebik:
-
| Sent...: Wednesday, August 25, 2010 8:50 AM
| Subject: You have been unsubscribed from the Cebiksite
| mailing list
| To.....: ...-at-gmail.com
| From...: cebiksite-bounces-at-cebik.com
-
As of this email address, unfortunately, I have to use it in
USENET against e-mail robot-reapers. I already sent you this
e-mail from my real e-mail address too.
Thank you very much,
Petros Zimourtopoulos
p...@grnet.gr
| ...
| Free-gratis is the MS Windows application VEMSA3D, which
| *everyone* can enjoy the production of it by simply following
| the fully-commented instructions we already gave at the third
| page, right column, of our paper:
| http://arxiv.org/abs/1006.0031
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A clarification is needed here: This is version 1.0 info,
which has to be seen in parallell with that of file
[install.txt] included in version 1.1 zip at:
http://code.google.com/p/rga/downloads/list
pez, SV7BAX
p...@grnet.gr
| ...
| Again, I would never look a gift horse in the mouth ... I don't
| find the lack of comments an surmountable problem. If you have
| a basic understanding of the concepts which a piece of software
| source deals with, it is relatively easy to locate them and
| comment/document them yourself. For example, when looking in
| software for routines and statements dealing with a circle, you
| would simple search for constructs dealing with area,
| circumference, diameter, etc. It is just a logical progression
| to look for those dealing with the implementation of the
| moment method. NEC source used in conjunction with these
| efforts makes it a tolerable exercise in reverse engineering
| the task ...
|
| I see nothing wrong with expecting someone to do a bit of work
| to get something for "free", LOL.
|
| Regards,
| JS
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That's right! Since -as you already said- there are various
aspects of "free". Therefore, there is no field of application
of term 'reverse engineering' especially under the licenses
'Free Libre Source Code' and 'Public Domain Source Code',
since there is nothing there to disassembly it.
Moreover, under these licenses, ethics impose to give in return
at least as much as you get. This is especially holds in VEMSA3D
case, in which we get the Source Code included in J.H.Richmond's
report:
"Computer program for thin-wire structures in a homogeneous
conducting medium"
or just
"Computer program for thin-wire structures"
from NASA Technical Reports Server at:
http://ntrs.nasa.gov/search.jsp
in the way already described in message:
| Sent......: Tuesday, August 24, 2010 8:59 AM
| Subject...: Re: vemsa3d 1.1 - a floss visual em simulator
| : for 3d antennas
| Newsgroups: sci.physics.electromag,rec.radio.amateur.antenna
| From......: <p...@grnet.gr>
Well, this source code has 1,044 lines of code, in 16 routines:
(1,044 = 100 + 61 + 158 + 36 + 9 + 98 + 120 + 104 + 40 + 64 +
+ 45 + 22 + 22 + 40 + 87 + 38)
and in return, we give for now:
* only 3 comment lines less than *
those exist among these 1,044 lines -as one can easily find
them in SGANT routine, at page 22, of the aforementioned
report.
Best regards,
pez, SV7BAX
John Smith
> ...
> That's right! Since -as you already said- there are various
> aspects of "free". Therefore, there is no field of application
> of term 'reverse engineering' especially under the licenses
> 'Free Libre Source Code' and 'Public Domain Source Code',
> since there is nothing there to disassembly it.
>
> Moreover, under these licenses, ethics impose to give in return
> at least as much as you get. This is especially holds in VEMSA3D
> case, in which we get the Source Code included in J.H.Richmond's
> report:
>
> "Computer program for thin-wire structures in a homogeneous
> conducting medium"
>
> or just
>
> "Computer program for thin-wire structures"
>
> from NASA Technical Reports Server at:
> http://ntrs.nasa.gov/search.jsp
>
> in the way already described in message:
> Best regards,
>...
> pez, SV7BAX
Yes. Well, "reverse engineering", apparently, has many different
meanings to many different people, as "free", also. However, all
reverse engineering, done by engineers, does not involve a disassembler.
Physical devices and concepts lend themselves well to reverse
engineering, also.
I certainly have no interests in implementing any of this in a
business/financial interest. And, since amateur radio itself demands the
concept of "giving back"; It is a well known tradition. I see no
conflicts with my directions, uses and interests.
NASA's contribution has already been paid for. NASA is the beneficiary
of public funds ... I am sure the taxpayers say, "Thank you NASA;" I
know I do.
Regards,
JS