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Software FAQs

What are the system requirements for Stella and iThink?

iThink and Stella are available in both Windows and Macintosh versions. Windows 10 or later and Macintosh OS 11 or higher are required. A 64-Bit operating system is required. A minimum of 4GB RAM is required, but at least 8GB is recommended.

Do Stella and iThink run on a 64-bit Windows operating system?

Yes, both Stella and iThink run natively on 64-bit Windows machines.

What is a Module?

A Module is a container for lower-level model structure. It is designed to support a process of top-down model design and development. For more information and frequently asked questions about Modules, read our Blog Post or our help page for working with modules.

What is Spatial Map?

Spatial Map is an option in the Interface window of Stella Architect that allows you to map array data in your model to color values or images so that you can view the data as three-dimensional, spatial information. In the spatial map, the x and y axes are defined by the bounds of the array and z is represented by a color or image. (Elevation and temperature are examples of z values.) For an example, see the Spatial Map page in the Help.

Can I customize the way my user interfaces look on the web?

Yes, by using the Stella Designer Developer Kit. Contact for more information.

How do I bend a flow?

Drop a flow and start dragging it. When you want it to change direction at a 90-degree angle, hold down the shift key while you move the cursor in the direction you want the flow to go. For more tips and tricks about using Stella, read our blog post.

How do I add another bend to a connector?

Drop a connector into the first variable and start dragging it. When you want it to add a bend, hold down the shift key while you move the cursor in the direction you want the connector to go.

How can I integrate my model with other applications?

If you want to link data to your model, you can set up dynamic data import/export links to Microsoft Excel or .csv files.

If you want to integrate your model with other applications, in some cases, you can use the command line.

How many times can I deactivate my license?

The isee software license manager allows two deactivations within a six-month period.

How do I install Lab Pack or Site licenses silently?

Please see the directions for silent installation in the Lab Pack installation instructions.

How do I prepare the interface of a version 10 model for Stella Architect?

Please see the documentation on using version 10 models in Stella Architect and Stella Professional: Using Version 10 Models.

Why do I sometimes get a "File not Found" message when opening a model?

Some models might have associated files that the model author added for various reasons, including:

  • Excel or csv files for data import and export
  • Picture files for graphics frames, modules icons, annotations, or buttons
  • Sound files for Buttons or simulations events
  • Movie files for simulation events or video object
  • Run data from previous simulations

When copying a model from one computer to another, you may need to copy more than just the model file. If your model uses other files such as graphics, sounds, or spreadsheets you’ll need to package all of them with the model file. For more details, read our Blog Post or our help page for distributing models.

Can I run a Stella or iThink model from a Windows or Macintosh command line?

Yes, you can open and run models from a command line. You can also perform other operations using the command line. For more details, read our Blog Post or our help page for running from the command line.

Do Stella and iThink support matrix arithmetic?

Yes, Stella and iThink support matrix operations such as addition, subtraction, transposition, multiplication, and division. You can also perform matrix multiplication with the PROD builtin function. For more details, read our Blog Post or our help page for array manipulation.

Can I create causal loop diagrams (CLDs) in Stella and iThink?

Yes, you can build causal loop diagrams by using the CLD editor, accessed from within the model diagram by clicking File -> New CLD. This will open a blank CLD page with a simplified tool bar designed for making CLDs.

Alternatively, within the normal model diagram window, you can use either name-only modules or name-only delay converters. Using modules, you can also link a CLD to a working stock and flow model. To learn more and see an example, read our Blog Post or our help page for building CLDs.

Why is storytelling (Stella Architect/Stella Designer) such a powerful feature?

Storytelling is a feature unique to Stella Designer and Architect that allows you to present and explain your model piece-by-piece. Even more powerful is the ability to show the behavior as the structure of the model unfurls. Through storytelling, you can clearly create and communicate the link between the structure of the system and the dynamic behavior. For more details, read our Blog Post or our help page for stories.

Can I install the software on more than one computer?

As the end user, you have access to two registrations of the software. You can register the software to two computers for your use only.

How do I move the software from my old computer to my new one?

Start by deactivating the license on your old computer. See How do I uninstall the software for details.

Once the software confirms the deactivation, you can uninstall it from the current computer and install and register it on the new computer. Please note that you can only deactivate your software twice within a six-month period.

Can I change the default color for my model entities?

Yes, you can change the default color of entities for each model that you build that will apply to all models you build after making the setting. The option is available in the “Default Settings…”, accessible from the Edit menu.

How do I change default model styles like the color of variables, font size, and variable name location?

You can change the default variable colors for a single model in the Model Styles Panel. You can change the default colors for all models in the Default Settings panel.

Looking for software help?

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