EMERGY SIMULATOR / News: Recent posts

JGraphpad Community Edition 5.8.0 is out...


we finally released JGraphpad Community Edition 5.8.0 after lots of heavy refactoring work.
The hope is that the new code is really cleaner, more extensible and easier to understand for new comers.

There are also some new features (few), among them: no need for all permission when executing via webstart, new XML encoding system (more versatile), per document toolbar allowing different documents to have different type of toolbars...... read more

Posted by Raphael Valyi 2006-03-22

Roadmap for the next EmSim release and webservices...

Hi all,

Here are the new foreseeable changes for the new coming Emergy Simulator release. First of all, Emergy Simulator 2.0 won't be released as 2.0. Indeed, we are changing the verionning policy to emphasis the JGraphpad version on which it's based. So the next version will propably be called New planned features are:

1) Better Fractal Aid integration: the FrAid console is going to be part of the document panel and the document layout will change.
2) Easier parameter table editing, including refresh button and color chooser (already in the CVS)
3) The simulation will probably listen at the graph model change events (if it's not too slow). Thus changing a connection could directly re-plot the simulation
4) Better server integration: it will be quite easy to load preselected examples at startup when clicking a javascript button in the webpage
5) Possible wiki integration (simulation files could be handled as wiki document in a wiki engine)
6) Correct the current bugs (see what's new for version 2.0)
7) No more need for unlimited security access (use tha JNLP API instead)
8) The shape toolbar is now an attribute of the document, meaning that depending on the document you decide to create you could easily get a specific toolbar... read more

Posted by Raphael Valyi 2006-02-06

new forum policy

Hi all,

Until now the forum has been divided in three categories: "Developpers", "Help" and "Open Discussion". But it appeared that users were posting help requests on "Open Discussion" instead of "Help".

So in the sake of clarity, we decided to remove the Help forum and let people request help on "Open Discussion" just as they did before. former posts form "Help" have thus been removed but those were very outdated anyay.... read more

Posted by Raphael Valyi 2005-11-25

updated version of the EmSim developer manual

Hi folks,

I'm pleased to announce that I finally almost finished the HOWTO I announced some time ago already. I've indeed been working for 20 months now with JGraphpad in order to customize it into an ambitious ecology/ thermo-economics simulator (EmSim) which is actually nonetheless but a graphical language based on the graph and bondgraphs theory.

For the JGraph team: you are welcome to improve and/or reuse this howto in your site of course.... read more

Posted by Raphael Valyi 2005-08-29

corrected web site, news and java 1.4.2 issue


1) I've just corrected the website. HTML files generated by Forrest after Latex2HTML processing weren't indeed rendered correctly since Apache Forrest is in its early stage of development.

2) By the way some site content has been added. Especially, the "what's new section" deals with the new features of EmSim1.3.1, see:

3) While I'm slowly making EmSim 2.0 which will be a major realease, some people reported a bug with EmSim 1.3.1 (either online or offline) with java 1.4.2. If ever you are in trouble to start EmSim, then try to upgrade your java version to 1.5.0. If you are still in trouble, let me know in the forum. The 2.0 version already fix this problem (I mean the experimental source code in the CVS repository).... read more

Posted by Raphael Valyi 2005-07-13

the JGraphpad code has been improved to improve reuse

Hi folks,

Instead of focusing on improving directly EmSim, those two last weeks, I focused on improving the basis: JGraphpad, the graph handling framework on which EmSim is based.

The last changes in JGraphpad can be seen at the CVS repository of the JGraph project:

Usefull comments I did might also be found in the JGraphpad forum at http://www.jgraph.com

Now that those improvements are done, I'll soon (< one week) realease a new EmSim version. The new source code will be much more simpler since reuse from the JGraphpad framework is slightly increased.... read more

Posted by Raphael Valyi 2005-06-23

get the last source code and changes with the CVS repository

Hi folks,

you're more and more numerous to get interested in that simulator. However, I can't spend much time to distribute it. Packaging official new versions is quite time consuming while it's better to improve the real functionalities. So the executable jar version will be quite up to date, but on the contrary, to get the last source code matching such a version and capturing the changes made, The best thing to do is to have a look to the CVS source code repository at sourceforge. You can also get all the last source tree if you use a java editor like Eclipse. The thing to do is "check out CVS from repository". Good luck, if you are in trouble, just let me know. And remember, Emergy Simulator is really customizable to feet your needs but it need new developers, see the "project status" section. Regards,... read more

Posted by Raphael Valyi 2005-06-08



In order to increase the communication about Emergy Simulator, I built a new website using Apache Forrest. This website is quite up to date (not everywhere still) and it's much more user friendly. Send me your feedback about it.

EmSim 1.3 (similar to the current webstart and applet version) will be officially realeased very soon also. New improvements will be documented as well. Regards.

Raphal Valyi.

Posted by Raphael Valyi 2005-06-02

EmSim 1.1 coming very soon...

Hi folks,

As I explained, I'm no more working on the project officialy but I do it in my free time. So after those few months I quite achieved the 1.1 version which fix numerous bugs. Among other things:
* now allows to save and open archives with java 1.5 also
* far better user interface
* shipped with JGraphpad 5.2 and may be even with 5.4
* added inductive storages
* lots of new things...

I'm also thinking about signing the applet in order to make it works online.... read more

Posted by Raphael Valyi 2005-02-23

EmSim quite unusefull on Linux due to a bug


i'm discovering that there is a major bug when usiong EmSim on Linux, you can't open archives (demo files) neither perform simulations, see the bug report:

NB: still this could be a bug of my java BlackDown 1.4.2 JVM installation but I don't believe it is.

EmSim 1.1 is also coming soon, but this bug will postpone a litle bit the new version...... read more

Posted by Raphael Valyi 2005-01-03

EmSim 1.0 archives not working with java 1.5!

Be careful: if you are using a 1.5 java virtual machine, then you won't be able to store your files and open it again (jgx files). Especially, you can't look at the examples provided in the demo files.

Indeed use the 1.4 java virtual machine or wait for EmSim 1.1. For more details about the bug, look at:
https://sourceforge.net/tracker/index.php?func=detail&aid=1065048&group_id=102093&atid=631100... read more

Posted by Raphael Valyi 2004-11-12

news about EmSim

Unluckly, it seems that it's now that I finished my work placement that EmSim encouters the larger success....

Still nobody is in charge of the project anymore. We still hope anyone will upgrade EmSim...

Anyway, I'm slowly making a 1.1 version. This version will definitely include an inductive storage model that will allow much more dynamic modeling abilities. For instance EmSim is likely to be used to model (for pedagogical purposes) rheological properties of materials. Of course, electric circuits will also be possible to model. This doesn't concern sustainable development. However, such abilities allow me to still developp a bit EmSim officially for other purposes and could allow more developpers code EmSim in the future. Indeed the dynamical kernel of EmSim could be used much more widely than systems ecology. In turn this will increase the quality of the software.... read more

Posted by Raphael Valyi 2004-11-04

Warning out of date website!


I see that more and more people get interested in EmSim and are writting to me. BUT, please notice that the website is not up to date! I will update it, may be this week end but I'm not sure.

Instead, download the report available at sourceforge, it's much more up to date.

I'm surprised because they'ar lot of people getting interested, so I'm willing to get imply a little bit more in the project to fix minor bug and help the transition for new developments.... read more

Posted by Raphael Valyi 2004-10-01

EmSim 1.0 released, succession needed


EmSim 1.0 is now available. It has a better user interface, especially when dealing with emergy. Examples are also now better intagrated in the application and come fully commented, so it's better for teaching.

I didn't understand really why the portuguese version for Brazil wasn't working so now I let the user force the translation by using the "Executar EmSim.bat" batch file.

The main changes are the use of JGraph 5.0.4, JGraphpad 5.0.3 and FrAid 1.1. This make the code a bit better and make easier future adapations.... read more

Posted by Raphael Valyi 2004-09-28

EmSim 0.9 released and EmSim 1.0 coming soon

EmSim 0.9 has a cleaner code and especially:
* a better user interface for dynamical systems
* the amplifier model is corrected
* amplifier and interaction now can have several outputs and the input flows will adapt themselves to provide the actual outflowing flows. This is specially usefull in co-productive processes and is necessary for dynamical emergy track summing.
* no more installation required.
* uses JGraphpad, JGraph 5.0 and FrAid 1.0... read more

Posted by Raphael Valyi 2004-09-14

EmSim 0.8 beta released!

This last version of Emergy Simulator:

*is very efficient for diagraming and simulating Odum's energy language dynamic systems.
*includes a demonstrive version of emergy track summing
*includes lots of dynamic samples from ecology/economy/social sciences
*includes the flipflop model (discrete event)
*is really evolutive and pedagogic since it uses Jgraphpad 5.0 as a library (yes it subclasses excactly was is needed).
*is easy to install since it include an installer that automatically set up FrAid correctly.... read more

Posted by Raphael Valyi 2004-08-18

EmSim 0.7 beta realeased!!

the version 0.7-beta is quite stable version for diagramming and doing classic dynamic quantity simulations)

Code migration:
is based on JGraphpad4.0 and JGraph 4.0
(see http://www.jgraph.com\)
(and FrAid: see http://www.fraid.org\)

Add the following features:
* dozens of dynamic models are now supported (but be careful, usupported models are: inductive storage and switch)
* support complex models with local variables that are then translated in their symbolic global name in the script
* allows to edit (copy for an other application like Matlab) and modify the differential system script
* everything is encoded and decoded as XML so the models you build will be easily compatible with future versions or other applications
* filter out some model parameters depending on the kind of simulation you are attempting
* better error message when a simulation doesn't work (the next version will include a true debugger)
* automatic autoscale and better graphic default settings
* better UI interface in general
* translated into brazilian portuguese by Marlei Scariot... read more

Posted by Raphael Valyi 2004-07-15



The website was very experimental and out of date. So I made a quite new one. You will find a fully useful user manual inside and lots of corrections in general.

Finally I opted for a simpler site. Th reason is that we want don`t want to block the site actualisation after the deadline of my work placement, because not everybody is used to PHP for instance.

Concerning Emergy Simulator, there is a anoying bug with the popup menu in version 0.6.
A solution is to open the JGraphpad_properties.txt file and to add RotateSelection and ConnectToSink inside the GraphPopup because undefined models will switch to the GraphPopup instead of providing their popup) whereas some options like rotation and sink symbol connection are useful for graphical purposes.... read more

Posted by Raphael Valyi 2004-06-25

EmSim 0.6 comings very soon!

Please, if you are interresting in Emergy Simulator, then wait for the version 0.6 (the version presentedin the workshop) that is coming saturday or monday. It provides much more models and offer a quite achieved interface for simulation. The version 0.7 is going to be a beta version since it will already be able to simulate most of the models from the Computer Minimodels Odum's book and since the code migration for jgraph 3.4.1 will fix the main bugs (like the unconnected edge saving error).... read more

Posted by Raphael Valyi 2004-06-19

EmSim 0.5 released

handle some dynamic simulations!
Open and simulate the providen examples to know more...


Handle XML file saving and recovery of the models and parameters.

fix lot of minor bugs.

the next version will probably be called beta since more models will be supported and since a migration to jgraph 3.4.1 will fix some bugs...

Posted by Raphael Valyi 2004-06-09

EmSim 0.4 released

EmSim now builds with ant apache since the build.xml file from JGraphpad has been udapted. So now the build process is easier even if you don't have any powerful IDE and it's platform independent. Only install ant apache (of course a java JSDK 1.3 or higher should also be installed) and then run it by default with the providen build.xml file.
WARNING: the FRAID (FRactal AID) package is required to intergrate the differential system and also to graph the result.... read more

Posted by Raphael Valyi 2004-05-20

EmSim03 released

This version is really clean in building cells form the modeling toolbar.
Cells now have models that store their parameters in the propertie has table. models are organised as a tree (they will inherit methods and implementation of interfaces). The tree is correctly handled by SubModelChooser and ModelFactory...
Models aren't correctly stored as XML but it's going to be quite easy now.
Dynamic simulation is coming soon.
More informations can be seen at:

Posted by Raphael Valyi 2004-05-04


A web site for Emergy Simulator has been released and can be found at:
This is a first version that will improve in the future while it will also move to sourceforge.
Depending on your browser it can work more or less.
At the time the site explains little about the code but more about the emergy methodology.

A 0.3 version is coming very soon, possibly today. Cell models are better handled, cell creation has been cleaned once again...... read more

Posted by Raphael Valyi 2004-04-28


A presentation release of this software will soon be available here. At the moment I'm working on cleaning my implementation of JGraphpad that allows user to drag and drop the specific symbols of Odum's energy meta-language.
Before the midle of Mars, a first beta release will allow a powerfull energy language diagramming (like some do with Visio spending lot of time, if not license money).
Before the end of Abril, a second release will allow experimental dynamic simulations (I already have made the algorithms on the paper).
Then I will focus on the Emergy algebra simulation following the solid formulation from Corrado Giannantoni.
At the same time, I will provide stable user versions and documentation. A specific internet site is also incubing and is going to provide clear explanations about the software but also about Emergy analysis, pretending this way be the first french speaking website dealing with emergy accounting.

Posted by Raphael Valyi 2004-02-20