# To open or exit a model

Release: 4.6  •  5.0  •  5.1  •  5.2  •  5.3  •  5.4  •  6.0  •  6.1  •  6.2  •  6.3

Models: An Analytica model is a collection of variables, modules, and other objects intended to represent some real-world system you want to understand. Between sessions, a model is stored in an Analytica document file with the file type “.ana”.

To open a model: One way to open an existing model is just to double-click the icon for the model file in the Windows directory.

Another way to open a model is to:

1. Start up Analytica by double-clicking the icon of the Analytica application, or selecting Analytica from the Windows Start menu. Analytica opens to the Intro screen
2. Click on the Open Model button on the intro screen. A file selection dialog appears to let you find the model file you want.
Note: You can alternatively press on the File pull-down menu, and select Open Model from the menu.

However you start a model, Analytica shows this progress bar as it reads in the model file.

Tip
Click the Stop button if you change your mind and decide not to open the model. It stops reading, resulting in a partially loaded model.

Next, it shows a progress bar as it checks the definitions of variables and functions in the model.

Tip
If you click the Stop button, it stops checking. Diagrams might have missing arrows and cross-hatched nodes indicating unchecked definitions. If you later ask to show the result of a variable, it checks any variables needed. Thus, clicking Stop simply defers some checking, and causes no problems with the model.

If the model contains any variables whose definitions are missing or invalid, they are listed in the Invalid Variables window. You can still compute results for variables with valid definitions, as long as they don’t depend on variables whose definition is invalid.

To close a model: To close a model, select Close Model from the File menu. If you have made any changes to the model, a dialog asks you whether you want to save the changes before closing. After the model closes, the Intro screen will again display.

To open another model: Analytica can open only one model at a time. To switch to another model select Open Model from the File menu. A dialog prompts you to locate and open another model. The model you are currently working on will be closed. If you have unsaved changes, you will be asked whether you wish to save those changes.

Example models: Several example models spanning several categories are installed with Analytica. You can quickly get to these either from the Analytica / Example Models shortcut on the Windows’ Start / Programs menu , from the More Example Models button on the Intro screen, or from within Analytica from File → Open dialog by pressing the Analytica Example Models button at the upper left.

To exit Analytica: To exit (or quit) Analytica, select Exit from the File menu. If you have made any changes to the model, it prompts you to save your model first.