Making Connections - Latest Comments

Re: Using PEST to Calibrate Models

Sarah Davie — Fri, 04 May 2012 15:41:21 -0000

STELLA and iThink have built-in functions for arcsin and arccos. The ACRCOS function gives the arccosine of expression. The ARCSIN function gives the arcsin of expression.

Re: Using PEST to Calibrate Models

F8at3 — Wed, 02 May 2012 20:02:46 -0000

HI, Would you please tell me that how to realize the arcsin and arccos funcions in sttela, thank you very much!

Re: Connecting iThink and STELLA to a Database

Nat Pierson — Mon, 09 Apr 2012 09:06:15 -0000

Charles,

Tried emailing you at the address you supplied, but the message keeps getting bounced back. Feel free to outline your issue on this forum or email support@iseesystems.com and we'll get you going. Thanks.

Re: Connecting iThink and STELLA to a Database

Charles — Sun, 08 Apr 2012 23:45:17 -0000

Hi my name is Charles, i'm trying test the funcionality connect SQL Server and stella 9.1.4, but i don't have good result, thanks a lot for your help, my e-mail: jhetfiel2010@gmail.com

Re: Spatial Modeling with isee Spatial Map

kchichakly — Mon, 27 Feb 2012 16:43:02 -0000

That is correct, it is an explicit method. This is because iThink and STELLA solve problems using numerical integration. The implicit method uses linear algebra, which is not the focus of our software.

Re: Spatial Modeling with isee Spatial Map

kchichakly — Mon, 27 Feb 2012 16:30:57 -0000

Hi Peter,

At present, the only way to show the dynamics unfolding is to keep pressing the Run button (or use Ctrl-R/Cmd-R). We will hopefully have better integration soon!
Karim
PS Thank you for explaining where to find spatial map.

Re: Spatial Modeling with isee Spatial Map

F8at3 — Mon, 27 Feb 2012 15:16:30 -0000

Hi ,thank you for your work, I really learned a lot. By the way, for the one-D heat transfer problem, your method is a explicit one, right? How to realize a implicit one?

Re: Tips, Tricks and Shortcuts for using iThink and STELLA

Neetu — Sun, 26 Feb 2012 08:26:09 -0000

gud...quite useful!!!!thanx...

Re: Matrix Arithmetic

Bhubaneswor Dhakal — Tue, 14 Feb 2012 23:18:29 -0000

I was looking for a real case example of transpose in Stella. For example I was looking for transposing a column vector "yield" to Area (array). I tried to open your example file in Pdf and other programmes I could not open it. None of my programme support your file. Would you please advise me the transposing technique and opening format of your programe>

Re: Building a Health Care Model Hierarchically

Rzaini — Tue, 31 Jan 2012 08:51:40 -0000

very interesting

Re: About

Necmi Tosun — Mon, 02 Jan 2012 11:27:12 -0000

Hi Cambell,

Please let me know your contact details.

Necmi Tosun (ntosun2000@yahoo.com)

Re: Spatial Modeling with isee Spatial Map

Peter Song — Sun, 01 Jan 2012 21:13:50 -0000

Another tip. I used a gif animator to produce a movie. I hope somebody can integrate Spatial Map and a GIF animator to get it in a one step. I tried to upload the animated GIF file but this site does not allow an animated gif...

Re: Spatial Modeling with isee Spatial Map

Peter Song — Fri, 30 Dec 2011 01:54:45 -0000

Finally I got it. I set the Pause Interval at 10 in STELLA's Run Specs and observed the changes by clicking the Run button 24 times at 10, 20,30,..., 80, ...150, 180,... 240. Check out the image below. To have this, I set the colorsetting in Spatial Map as below.

Re: Spatial Modeling with isee Spatial Map

Peter Song — Fri, 30 Dec 2011 01:07:06 -0000

Question: I have to keep pressing the "Run" button to see Spatial Map change. Is there any way to see it changed continuously like in a movie? I am modeling a spread of Foot-Mouth disease and audience will be more pleased to see a movie rather than a series of static images flickering...

Re: Spatial Modeling with isee Spatial Map

Peter Song — Fri, 30 Dec 2011 01:03:54 -0000

Not much discussions going on... Spatial Map is only included in the full license version, not in the Trial version. I had to buy STELLA 9.1.4 to see it running. It is installed in the STELLA folder.

Re: 2011 Barry Richmond Scholarship Award

Joanne Egner — Wed, 28 Dec 2011 11:51:05 -0000

Hi Rahayu,

You may want to connect with the System Dynamics Society (www.systemdynamics.org). The link to their discussion forum is right on the home page. There also are a number of system dynamics practitioners connected via LinkedIn that could be helpful.

Good luck!
Joanne

Re: 2011 Barry Richmond Scholarship Award

Rahayu S Arifin — Mon, 26 Dec 2011 07:45:50 -0000

i would like to participate the system dynamics expert discussion, eventhought I am still far for being understand the system dynamics. I use this methodology for my disertation on water supply system . The case study is Bandung - Indonesia. How to be registered as participant ? Thanks to reply this message.

Re: Spatial Modeling with isee Spatial Map

Peter Song — Fri, 23 Dec 2011 00:00:44 -0000

Where is the Spatial Map? I am a STELLA version 7.x user and wish to upgrade to 9.1.4 for Spatial Map. I downloaded a Trial version but can't find Spatial Map there?

Re: Private: Steady-State Initialization of Conveyors

Mac — Sun, 27 Nov 2011 15:08:16 -0000

Please explain why exponential leakage cannot be 0 (either set to 0 during sensitivity analysis, or set to 0 for initial conditions, or calculated to become 0 as a result of model feedback.

Re: Published Papers that Feature Models

Krish — Wed, 16 Nov 2011 13:50:12 -0000

Hi jeremy

I am a beginner in "system dynamics", and I am trying to implement the given article
regarding supply chain. Can u help me with devoloping graph for the model as it includes summation of model variables.

Saeed, K. (2009). Can trend forecasting improve stability in supply chains? A response to Forrester’s challenge in Appendix L of Industrial Dynamics. System Dynamics Review, 25(1), 63-78

PDF : http://onlinelibrary.wiley.com...

Re: Running Models from the Command Line

isee systems, inc. — Thu, 20 Oct 2011 09:31:26 -0000

Brandi,

Yes, the help file link in the post shows the complete list of command line arguments:
http://www.iseesystems.com/Hel...

After adding the command line option in v9.1 as an experiment, we have been surprised pleased to see how many users take advantage of it. Logging, status and verbose mode switches are definitely features we would like to add in the future. Thank you for the feedback.

Re: Running Models from the Command Line

Brandi — Wed, 19 Oct 2011 12:38:42 -0000

I've seen the list of command line options, but are these the only options available? Is there anyway to output, such as verbose to the command line screen (such a progress indicator, which model run, etc). If a verbose or log option is not available, will it be made available in future versions?

Re: About

isee systems, inc. — Tue, 18 Oct 2011 11:14:31 -0000

This is a bug in the present version of iThink and STELLA. Without Excel installed on your system it makes it more difficult, but not impossible, to import data from CSV files. We are correcting this problem in the upcoming release.

How to Import Without Excel from a CSV File:
The specific import feature that gets adversely affected is the ability to maintain a persistent link to an import data file. As you probably have discovered, if you try to manage the persistent links, you'll get an error that Excel is not found. What you can do are one-time imports of CSV files.

If you go to the Edit menu and select "Import Data", choose the "One Time" import type and select your CSV file, this should work on the subsequent run. You will have to manually set this up again if data changes in the imported CSV file.

Exporting to a CSV file without Excel installed works without any problems.

Re: About

Stanhopkins — Mon, 17 Oct 2011 19:36:31 -0000

It seems the iThink software cannot import data into a model unless Excel is installed on the same system. Booo! I'm using Open Office and don't have it installed. Even a raw .csv file cannot be input unless it is read by Excel and presented to your software. This should not be.

Re: Tip: Setting up imports for 2D Graphical Functions

Sdavie — Thu, 11 Aug 2011 10:36:57 -0000

I am afraid I don't understand your question. Please e-mail support@iseeesystems.com so we can discuss further. Thank you!