Talk:System dynamics/Archive 2

New example image
I just created a slightly less complicated example image depicting system dynamics... Should be considered for inclusion:

http://flexo.sipsik.net/4d_systemdynamik.svg 92.226.118.229 (talk) 20:37, 5 May 2011 (UTC)

Ptolemy and System Dynamics?
I've read about Ptolemy from UC Berkeley - []. This seems to talk about Systems Dynamics, but it's all in terms of modeling embedded or electrical systems. Is this not quite the same thing as discussed on the SD page? —Precedingunsigned comment added by72.248.107.194 (talk) 15:54, 16 April 2008 (UTC)

Different meanings of "System Dynamics"
I am not sure if this is the same point that the above user made, but I found this page in an attempt to find information about mechanical systems and their simulations. ("physics" "dynamics" "system", etc. "System dynamics" is occasionally said while referring to movement and changes within a 'physics engine' or other package of mechanics or electronics. I think this is worthy of a disambiguation page or a "not to be confused with" line.

In contrast to the rest of the "Systems Dyanimics" page, there is a 3D model animation involving a piston at the bottom, which is related to what I sought, but with basically no information about the software or related concepts -- only that it is related to the rest of the page as it represents a sort of system. Perhaps a split is necessary between electric/mechanical systems and social/influential/relational systems and the software used to simulate each. No offense intended to the group dominating this page, but it seems hard to give meaningful, stable units to the elements in influential systems -- perhaps that can be a determining factor in the split. 68.80.179.150(talk) 09:52, 25 January 2011 (UTC)John/CP44

Agreed, there seems to be no relation between the 4D model and the rest of the page. I think it should be removed. Renduy (talk) 03:33, 14 March 2011 (UTC)


 * I am the copyright owner of the software used to make the 3D model animation involving a piston. You can find it on my website true-world.com


 * I added it in response to section : To-do list 4 : "Provide examples in domains other than population dynamics."


 * I have not mentioned the name of the software because of this section : Examplespam, linkspam
 * Patrhoue (talk)Patrhoue 19:17, 23 March 2011 (UTC)

History
It would be kinda cool if there was a "History" section.

-- TimNelson (talk) 06:33, 24 October 2008 (UTC)


 * Hi Tim. I created some of a history based on a public domain source. You can read more in that online work. Good luck. -- Marcel Douwe Dekker (talk) 12:30, 24 October 2008 (UTC)

Request for review of plateau principle entry
I have created an entry for the Plateau Principle that discusses different aspects of practical, biological system dynamics and includes references to the literature as it applies to system dynamics. This is a new, unreviewed entry that can be found by searching for plateau principle. I would like to request a review by a person with expert knowledge of system dynamics. It would be useful to add a link to this new article if deemed appropriate. Once a review has been done, please delete this section and provide comments in the talk section ofPlateau Principle. Many thanks, Jhargrov (talk) 13:50, 10 October 2009 (UTC)James HargroveJhargrov

Software
The following list of software that supports System Dynamics modeling and simulation was originally part of the Systems Thinking page, but probably belongs here. Any objections to adding it to the Software section?
 * AnyLogic (non-free software, supports system dynamics, agent based and discrete event modeling)
 * Consideo (free software combination of different methods, e.g. system dynamics)
 * Forio (non-free web-based system dynamics software with a zero cost version)
 * MapSys (non-free, zero-cost system thinking software)
 * Powersim (Commercial system dynamics software)
 * Powersim Solutions (internet-based simulation delivery software platform)
 * Simile (non-free System Dynamics software with object-based concepts)
 * Stella and iThink (Commercial system dynamics software)
 * Vensim (non-free zero-cost software for educational and personal use)

Thopper (talk) 09:09, 23 December 2008 (UTC)
 * Yes. It shouldn't be added per WP:EL and WP:NOTLINK --Ronz (talk) 17:48, 25 June 2009 (UTC)

Could someone please explain why the links to "free software" alternative for system dynamics, have been removed from this article. Here are the links I had posted earlier.


 * http://sourceforge.net/projects/sphinxes/
 * http://sourceforge.net/projects/system-dynamics/

Seems to me this article is being turned into an advertisement for true software.

balbirthomas (talk) 23:21, 07 August 2009 (GMT) —Preceding unsigned comment added by Balbir Thomas (talk •contribs)
 * I agree - it does indeed seem like this article is being turned into a rather chaotic advertisement for a commercial product, which is not the point of Wikipedia.Jimjamjak (talk) 10:43, 1 July 2011 (UTC)

Simulation
Would it be instructive to mention that system dynamics simulations are continuous simulations, as opposed to discrete event simulations? This follows the distinction made in the Simulation language page, and has some practical value in understanding the structure of systems dynamics simulations and locating suitable software. I propose adding a suitable mention to theOverview section.

Thopper (talk) 09:30, 23 December 2008 (UTC)

Stella/iThink vision
This article offers only Stella/iThink illustrations and, perhaps, "vision of world". Need new "not-Stella-view" writers. —Precedingunsigned comment added by143.107.230.53 (talk) 12:29, 25 January 2009 (UTC)

Criticism
A criticism section is curiously absent from this article. In fact, the whole article talks very positively about system dynamics in a way that might not represent the full spectrum of scholarship on the subject. —Precedingunsigned comment added by18.111.50.147 (talk) 18:44, 1 February 2009 (UTC)


 * Overview articles like this can always use a criticism section. If you want to start one, be my guest. -- Marcel Douwe Dekker (talk) 19:58, 1 February 2009 (UTC)

Examplespam, linkspam
I agree User:Ronz just removed a list of examplespam/linkspam, see. If I am not mistaken these links are to www.sphinxes.org, sourceforge.net, vensim.com are regularly put back here.

I wonder if these website can't be added on a spam list, if that is possible? --Marcel Douwe Dekker (talk) 17:20, 25 June 2009 (UTC)
 * I didn't look to see how frequently and widely the links were being added. I've looked a bit since, but don't see a large problem.  Still, it might be worth reporting at WT:WPSPAM. --Ronz (talk) 17:46, 25 June 2009 (UTC)


 * Ok. Maybe better just wait and see, for now. -- Marcel Douwe Dekker (talk) 17:59, 25 June 2009 (UTC)

TRUE (software) illustrations
As previously requested above, I could add new illustration : picture and comments.

This new not-Stella view, will come from software TRUE proposed byTrue-World, software made by me.

Is that possible, considering the required link ( linkspam or not ?) associated with this new picture, toward my website ?

Thank you, Patrhoue (talk) 07:03, 30 June 2009 (UTC)


 * What website are you talking about. There is no problem mentioning that website on a Wikipedia talk site. -- Marcel Douwe Dekker (talk) 15:07, 30 June 2009 (UTC) P.S. I removed the html tags in your previous comment, which are not needed here.


 * Oh yes, my website is www.true-world.com, it presents my work : a system dynamics software.
 * If you authorize me to add new picture (a snapshot of my software) in the System Dynamics page
 * how fill the field Source of this new picture : Snapshot from software TRUE, presented on (html tag) www.true-world.com (true-world) ?
 * Patrhoue (talk) 16:33, 30 June 2009 (UTC)


 * Ok, thanks for showing your proposal here. When I looked at that website all I saw were, what seems to be computer graphics and computer graphic animations. That didn't makes sense to me.


 * This animation proposal seems great, and we could even consider adding it on top of the article. In Wikipedia however, when there are any signs of commercial links, these images tend to be removed. So I can't guarantee anything.


 * It is the same with the image description. If you upload the file I would upload it on Wikicommons and not here on the English Wikipedia, because with images every Wikipedia (English, Dutch, German, French... etc.) has his own archive. And Wikicommons serves them all. Just make an account their and upload the file. If you give the ''Snapshot from softwareTRUE, you would probably also have to prove you are the copyright owner of the TRUE software. (Normally this is done by sending an email to the OTRS archive, but this should only be started if people start asking questions). To avoid this, you could already start explaining on the userpage of your new account.


 * I hope this helps. Good luck again. -- Marcel Douwe Dekker (talk) 11:35, 3 July 2009 (UTC)


 * Good, I'll do that! Thanks again for all. -- Patrhoue (talk) 14:51, 3 July 2009 (UTC)


 * Adding the illustration on top looks great. I however don't know how much more illustrations you could/should added? -- Marcel Douwe Dekker (talk) 16:24, 9 July 2009 (UTC)


 * I have deleted one image and modified the others, I think that page is good now ? --Patrhoue (talk) 18:05, 10 July 2009 (UTC)


 * No, I liked this layout here back, with both of the images. I don't restore it myself (yet), because I am not sure what other improvements you made.


 * I think there has to be a balance between those "animated gif's" (is this the right term) and the traditional jpg images. Three of those animations seems ok with me in the current state.


 * If you want to add more more of your work, I propose you add them to other articles. As I said before I am not really familiar with this line of work, and this seems a far deal, I mean a good balance. And I express this opinion here, so any other can agree (and say noting) or disagree (and comment here). -- Marcel Douwe Dekker (talk) 18:57, 10 July 2009 (UTC)


 * Ok. I already noticed you started adding these animated gifs in the Stock and flowarticle. As you can see I restored the static illustration because, I think, the explains the context. And the animated gif explains the dynamics. I don't think the one is better then the other. They are just different. Putting the two together makes sense to me. --Marcel Douwe Dekker (talk) 19:06, 10 July 2009 (UTC)
 * P.S. This is also the reason why I would like that static illustration back here.


 * I agree, old revision is restored, thanks.-- Patrhoue (talk) 03:59, 11 July 2009 (UTC)


 * Ok, thank you. -- Marcel Douwe Dekker (talk) 12:29, 11 July 2009 (UTC)
 * P.S. I don't understand what you mean with the caption of the first image: Systems dynamics modeling, John Sterman 2001. Could you explain...!?


 * This caption was in previous static image, I modify it, Thank you.Patrhoue(talk) 05:53, 12 July 2009 (UTC)


 * Thanks. Now I understand. -- Marcel Douwe Dekker (talk) 15:23, 12 July 2009 (UTC)

Simulation results
In the Simulation results section, the curve Imitators of the chart Adoptionseems to be like the curve New adopters of the chart Adoption in following sectionDynamic stock and flow diagram. That is perhaps related with the to-do-list task 5: Correct initial condition for example simulation. Perhaps initial condition is good and chart of the Simulation results section is not correct. If that can be verified, task 5 should be: Correct the chart Adoption of the Simulation results section ? Patrhoue (talk) 14:58, 4 July 2009 (UTC)
 * After verifying this model, the chart Adoption is not correct.
 * The Simulation results section is now in the new Dynamic simulation results section, without this chart.
 * The not necessary task 5 of the to-do list is now deleted.
 * Patrhoue (talk) 12:48, 7 July 2009 (UTC)

To-do list 4
New exemple Piston added, see the to-do list task 4: Provide examples in domains other than population dynamics.
 * Patrhoue (talk)Patrhoue 19:20, 24 February 2010 (UTC)

For this picture, can you specify exactly which software was used to create it? —Preceding unsignedcomment added by 99.70.118.36 (talk) 15:26, 9 March 2010 (UTC)


 * Thanks for your question, this illustration was made with software TRUE (Temporal Reasoning Universal Elaboration) True-World
 * step 1 : create the model and compute it
 * step 2 : create the scene with the 4D modeler and link the results with its components
 * step 3 : export the scene with the results into a binary file (.tru)
 * step 4 : play the scene (stored in the binary file) with the program TrueRender.exe

Patrhoue 19:16, 18 March 2010 (UTC) —Precedingunsigned comment added by Patrhoue (talk • contribs)

Vendor List
Why was the vendor list removed? I have undone (restored) the list. Please provide some arguments for its deletion, I think it is valuable content. —Preceding unsigned comment added by201.130.71.138 (talk) 22:48, 5 August 2010 (UTC)
 * See WP:EL. Mdd (talk) 23:22, 5 August 2010 (UTC)

Distracting images
I find that the rapid animation of the images on this page detract considerably from its readability. Anyone care to second that or disagree?Jimjamjak (talk) 10:47, 1 July 2011 (UTC)

The Piston Simulation
It kind of comes out of left field. There is no preface or explanation of the image and section's relevance. The only reason why you (the reader) would know that the original author of this subsection had not made a mistake is that the smaller picture shows that half of the pane includes the same type of flowchart/chemical equation type of specialized notational diagram depicted in previous sections. There are no words, descriptions or titles that connect this section to the overall text. "In this example the crank is driving, we vary both the speed of rotation, its radius and the length of the rod, the piston follows." That's it? It seems a bit unclear as to how this graphic connects to the concept of systems dynamics as a whole. It actually took me more than a few seconds to satisfy myself that the original author had not mistakenly added this graphic and was not simultaneously editing an article about CAD in another tab and simply accidentally pasted it here. To be more clear, might we not instead add something like: '''This is another graphical representation of the same dynamical model depicted above. In this case we use a simple mechanical model as an alternative and complementary depiction of the complicated and specialized notation used in the other diagram.'' Also that sentence: "In this example the crank is driving, we vary both the speed of rotation, its radius and the length of the rod, the piston follows. Is very poorly written and possibly grammatically incorrect.  If you did not wish to change it, you should use a semicolon for the "nested" list (semicolons are a bitch, amirite?).  Realistically though, I believe it merits complete rewriting.  Example:  "In this example a crank, with variable radius and angular frequency, is driving a piston with a variable connecting rod length."  THAT is by no means ideal.  It is still clunky.  But it removes the issue of the "nested" list punctuation issues.  It maintains the overall sentence structure used in the original.  Ideally, we would add a sentence that more clearly connects this subsection to the article as a whole, in addition to this descriptive sentence that annotates the animation.68.6.76.31 (talk) 03:55, 3 August 2011 (UTC)
 * Thank you, I tried to change the text as you suggested.Patrhoue 08:41, 4 August 2011 (UTC) — Preceding unsigned comment added byPatrhoue (talk •contribs)