Why not contribute to Ascend? Sim42 license issue
chris_dk
I have been following the discussions here regarding an open source
process simulator.
Regarding Ascend (http://ascend.cheme.cmu.edu/), is there any reason
why you didn't contribute to that project instead of starting a new
project (opsim)? I'm just curious.
Also, regarding the Sim42 license, it seems that is not compatible
with GPL because of the advertising clause. So if you want to create a
new project the Sim42 source code is a dead end if you intend to use
the GPL (my take).
I'm really interested in an open source process simulator because of
the idea sharing and also because of the opportunities for small
companies to having a working simulator without paying more than
10,000 euros for Aspen.
Best regards,
Christoffer
Dudley, Jeremy
but poorly documented - typical from PhD code. Sim42 was seen as a good
starting point, but using Python rather closed off from
'engineering-type' software developers. So the decision was made to
start from scratch, but using Sim42 as a source of ideas - so probably
getting around the licensing issues; and the core team chose Pascal
because they felt comfortable with it; those of us more on the outside
generally would have been happier with Visual Basic (frowned upon
because of the proprietary nature of the language) for the GUI and
Fortran for the maths side, or some variant - possibly C rather than
Fortran. ASCEND was moribund, at least as far as the web pages
indicated, with no obvious contact to see how it could be reused. The
available download did not provide source code, and there was no
friendly user interface - it was still firmly in the days of the
'punched card', requiring a text-only interface for creating the data
files, and no help on their creation - so you needed to know the various
keywords. The new ASCEND (ASCEND V?) still appears to come from the
command-line world, rather than the GUI world.
OpSim, as you know, soon petered out - working for free means that there
are always other pressures, and using Pascal meant that some possible
helpers chose to look elsewhere. The originator of the idea of 'Sim42
reborn' posted on http://opensource.cheme.info/ his thoughts on the
OpSim outcome.
As a note, Sourceforge has several attempts to build a Sim42 follow-on:
http://sourceforge.net/projects/ollints/
http://sourceforge.net/projects/opencheese/
http://sourceforge.net/projects/opsim/
And on an associated note, for wastewater flowsheet modelling, we have a
further two:
http://sourceforge.net/projects/killarney/
http://sourceforge.net/projects/openwwtp/
These have yet to deliver, and I haven't looked at the checked-in code.
Hi,
Best regards,
Christoffer
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Matt Henley
end user needing to set up equations to model a separation train. I
was wanting something more in line with Hysys or Promax. I agree, I
recall that they changed the license after we decided on which
direction we were trying to go.
We looked at licenses and understood that we could not use code from
Sim42 without addressing the attribution portion of its license if we
were going with the gpl. But then, it was pretty obvious that the
people involved did not want to use python so this was not too big of
an issue.
Eventually, we also wanted to use Open-CAPE as a guideline. I agree
with Hazem that Open-CAPE was too complicated for what we needed as a
starting point.
There was a lot of discussion about the language. Several each
wanting Visual Basic, C#, VC++. We had a poll and FPC/Lazarus won
(think 3 people voted for it).
Thanks for the link to Hazem's thoughts, I had not read that.
My advice for anyone wanting to start on something like OpSim (or any
open source project for that matter):
Don't announce anything. Don't form committees. Don't take votes.
Don't spend time having long email discussions on the name, language,
database backend, requirements, license, etc.
Write code in whatever environment makes you productive.
When you have something that works for your minimum set of
requirements, announce it and let people adapt to your decisions if
they want to contribute.
Fixing and extending is much easier than creation. Having 12 people
argue for days about the name of a program then 9 disappearing when it
comes time to code is incredibly demotivating.
Matt Henley
Daniel
dwsim.inforside.com.br). It is programmed in VB.NET using the free
version of Visual Studio (Visual Basic 2005 Express Edition). It has
many features implemented, including full VLE calculations with cubic
equations of state (Peng-Robinson, Peng-Robinson with Wong-Sandler
mixing rule, SRK), activity models (UNIFAC only so far) and
corresponding states models (Lee-Kesler). It also includes basic
methods for calculation of thermal and transport properties of single
and multi-component streams, the majority of it taken from the book
"The Properties of Gases and Liquids".
If you see the screenshots of the lastest public version (http://
dwsim.inforside.com.br/Galeria/tabid/54/path/dwsim12/Default.aspx),
you'll notice that it already is in a very advanced stage of
development. There are some basic unit operations implemented (valve,
expander, compressor, pipe, mixer, splitter, heater, cooler, gas-
liquid separator, etc) and utilities (phase envelope builder, special
binary phase envelopes, hydrate calculations, true critical point,
etc). For now i'm studying to implement reactors, and heat exchangers
will come later. After these I plan to implement towers (distillation,
absorption and stripping), which in my rumble opinion, are the most
difficult ones due to the 8712638712 possibilities of use. But we have
to start with something, right? ;-)
I agree that documenting the software is the most boring part of the
development process, but is a very important one. DWSIM is now fully
documented with online help and manuals (methods of calculation, user
guide and operations and utilities guide). The only problem for most
of you is that it comes only in Portuguese Brazilian (my native
language), but before I start implementing reactors I'll try to
translate it in such a way that it could be easily translated to any
other language supported by the .NET Framework by anyone who wants to
do it.
I'll let you know as soon as I finish the translation to english, then
you can use it and tell me what you think. Depending on the feedback,
we can talk about "larger" things like open-sourcing it.
Regards,
Daniel W.
> > To read our latest newsletter visithttp://www.wrcplc.co.uk/default.aspx?item=689- Keeping our clients up-to-date with WRc's business developments
> > -------------------------------------------------------------------------------------------
> > Visit our websiteswww.wrcplc.co.ukandwww.wrcnsf.com, as well aswww.waterportfolio.comfor collaborative research projects.
> > -------------------------------------------------------------------------------------------
>
> - Show quoted text -
chris_dk
> Hi guys, i'm developing a free simulator called DWSIM (http://
> dwsim.inforside.com.br). It is programmed in VB.NET using the free
> dwsim.inforside.com.br/Galeria/tabid/54/path/dwsim12/Default.aspx),
> you'll notice that it already is in a very advanced stage of
> development. There are some basic unit operations implemented (valve,
> expander, compressor, pipe, mixer, splitter, heater, cooler, gas-
> liquid separator, etc) and utilities (phase envelope builder, special
> binary phase envelopes, hydrate calculations, true critical point,
> etc). For now i'm studying to implement reactors, and heat exchangers
> will come later. After these I plan to implement towers (distillation,
> absorption and stripping), which in my rumble opinion, are the most
> difficult ones due to the 8712638712 possibilities of use. But we have
> to start with something, right? ;-)
> I agree that documenting the software is the most boring part of the
> development process, but is a very important one. DWSIM is now fully
> documented with online help and manuals (methods of calculation, user
> guide and operations and utilities guide). The only problem for most
> of you is that it comes only in Portuguese Brazilian (my native
> language), but before I start implementing reactors I'll try to
> translate it in such a way that it could be easily translated to any
> other language supported by the .NET Framework by anyone who wants to
> do it.
> I'll let you know as soon as I finish the translation to english, then
> you can use it and tell me what you think. Depending on the feedback,
> we can talk about "larger" things like open-sourcing it.
runs Windows.
If you have implemented it without using any P/Invoke and not relying
on any platform specific stuff, it should be possible to run it on
Linux using Mono. Only problem is that Mono does have much better
support for C# than VB.NET so using VB.NET limits your audience - but
I don't know if it is a problem for you.
chris_dk
From the screenshots on your main homepage it looks like you have come
very far seen from the interface point of view.
How are you developing this? In your spare time?
I found out how to view your screenshots in the gallery.
Regards,
Chris
Step
From the site it is obvious that you have achieved
a lot, but it's a pity that there is no English translation.
I think you should get one as soon as possible.
And if you make your project open-source,
people will surely help you with translation.
It is very big peace of work, so you can hesitate about
open-sourcing it. But you should know, that even if you
release it under open-source license you will still
hold the copyright on all your code, and thus will have
the right to release it commercially.
The best idea is to open it under GPL license, since
nobody will use your code in closed source products.
Regards.
Step
Daniel
like thermodynamics and programming to do something like this... apart
from really like doing it, my objective with DWSIM is to make it a
reliable process simulator to be used by students - and maybe by
professionals - who knows?
Every external component used in the development of DWSIM can be
downloaded for free on the internet. The main PFD area is based on the
article "Creating a Design Surface Using Windows Forms and GDI+ in
Microsoft .NET" (http://msdn2.microsoft.com/en-us/library/
ms973830.aspx), but only based - i've tweaked it and added lots of new
features in order to make it more adequate for the it's use. The
Office 2007-like style is due to "Krypton Toolkit" from
ComponentFactory. The dockable window style is there thanks to Weifen
Luo's DockPanel. Graphs are handled by ZedGraph. There are a lot of
other free components that provides many useful funcionalities to the
simulator.
I tried to avoid using COM DLLs but i didn't found any free .NET
component to solve linear systems of equations and non-linear data
fitting (necessary to generate the Ideal Gas Cp, Liquid Viscosity and
Vapor Pressure coefficients for crude oil pseudocomponents and
hypoteticals). Thankfully I found XNumbers and DMFitter, they do their
job well... hehehe
Regards,
Daniel
Daniel
files and translate them externally... the problem is that i could not
bring my computer with me to where i am right now, so i cannot do
anything before march 30. In the end of the first week of April i
should have something for you guys to test.
The idea of open-sourcing my simulator really makes me happy... but is
something to think very carefully about. I'll read the GPL license
text right now.
Wow, sorry for my english in the previous message. I was in a hurry.
Almost lost the bus! ;-)
Daniel
chris_dk
[SNIP]
> > nobody will use your code in closed source products.
closed source products. However, if the code is distributed the user
must be able to access the code either for free or by paying a fee.
Using the GPL ensures freedom for its users, that's why the FSF coined
it Free Software.
Regards,
Chris
chris_dk
> I tried to avoid using COM DLLs but i didn't found any free .NET
> component to solve linear systems of equations and non-linear data
> fitting (necessary to generate the Ideal Gas Cp, Liquid Viscosity and
> Vapor Pressure coefficients for crude oil pseudocomponents and
> hypoteticals). Thankfully I found XNumbers and DMFitter, they do their
> job well... hehehe
code for a lot of numerical techniques or you could take a look at the
python numpy and scipy modules and convert the code to VB.NET or C#.
Regards,
Chris
chris_dk
> files and translate them externally... the problem is that i could not
> bring my computer with me to where i am right now, so i cannot do
> anything before march 30. In the end of the first week of April i
> should have something for you guys to test.
should go to *.resx files. Then you can get a string like
"Resources.VAPOR" which gives you the string in the language the UI is
running in.
At least that how it's done in C#.
Regards,
Chris
Daniel
> This should be fairly easy to implement in .NET. Numerical Recipes has
> code for a lot of numerical techniques or you could take a look at the
> python numpy and scipy modules and convert the code to VB.NET or C#.
time to do this. I've even got one method (Brent) from this book to
solve a non-linear equation, that works very very well.
> Localization is built-in in .NET so all language specific strings
> should go to *.resx files. Then you can get a string like
> "Resources.VAPOR" which gives you the string in the language the UI is
> running in.
Designer, but I found a way to do it in for the entire application.
This way, only one .resx file for each language is sufficient, with a
call to a function like
"FormParent._ResourceManager.GetString("PropPack_PSFlashTempError",
FormParent._CultureInfo)" to get the localized string depending on the
current culture info. The problem is that I have more strings coded
programmatically than in the designer. So i'll have to write a program
to extract these strings and replace them with a call to that function
above... this is easy. The translation itself it that is time-
consuming.
> As far as I know, the GPL does not prevent the use of the code in
> closed source products. However, if the code is distributed the user
> must be able to access the code either for free or by paying a fee.
money using my code... but hey, this can happen independently of the
type of license. Anyway, i believe we have more benefits than
drawbacks in making the source-code available to everyone. Many people
should've a cracked copy of HYSYS or ASPEN already, so this should not
make a big difference to them. Just my thoughts.
To make it clearer, it was never my intention to make money with
DWSIM. I already have a great job in the biggest company in my
country, so this is much more like a "hobby" to me than anything else.
My company has it's own process simulator, a pretty good one indeed.
Fortunately, I can help them in areas other than the simulation/
modelling one.
Well, I just want DWSIM to be useful to someone. Unfortunately, as i
said before, you will have to wait some days to see if it can be
useful for you and, hopefully, for the the rest of the community as
well.
Daniel.
[guys, please let me know about the errors in my english text... it
will get better with time, I promise... hehe]
Matt Henley
>> closed source products. However, if the code is distributed the user
>> must be able to access the code either for free or by paying a fee.
>
>See? that is my biggest concern... other people can easily make some
>money using my code... but hey, this can happen independently of the
>type of license. Anyway, i believe we have more benefits than
>drawbacks in making the source-code available to everyone. Many people
>should've a cracked copy of HYSYS or ASPEN already, so this should not
>make a big difference to them. Just my thoughts.
Just to clarify. GPL code cannot be legally used inside closed source
projects if that project is distributed (such as selling a binary
version) as closed source programs don't by definition don't meet the
GPL's requirements. However, if a company wants to use gpl'd code for
an internal project (as long as they don't distribute), that would be
allowed.
It would legal for others to sell your work under the GPL as long as
they abide by the rules of the GPL. Of course, their customers could
redistribute the code for free.
You as the author, however, could issue the code under multiple
licenses. Trolltech's (now Nokia's) QT is a prime example of this, it
is GPL for GPL projects and they also sell it as commercial product.
However, if you go this route you have to get the people who might add
code to allow for its inclusion into your commercial product. This is
usually done by requiring they assign copyrights to you.
The standard way to make money from open source projects is to have a
customer that wants a feature and is willing to pay you to write it
and include in the GPL'd program or in a non-distributable internal
version, if the bit they want is proprietary.
What I have written is my understanding of the GPL. I recommend you
read at least the FAQ for it before releasing anything, here it is in
Portuguese http://www.gnu.org/licenses/gpl-faq.pt-br.html but I am not
sure it is as complete as the english version:
http://www.gnu.org/licenses/gpl-faq.html
Matt
Daniel
About the translation, I've already started it some weeks ago, but
it's stopped in these days by reasons explained above. Here is a link
to a screenshot of the "Welcome" screen already translated to English.
It came out pretty good actually...
http://www.inforside.com.br/dwsim_en.jpg
Regards,
Daniel