Import Data dialog box

Use the Import Data dialog box to select the options you want to use when importing model data from a linked Excel file. For more information, see Setting Up Import Links.

To open the Import Data dialog box, choose Import Data from the Model menu.

Make Template

Click on this button to create a template for importing all model constants and graphical functions. This will open the Create Import Template dialog box and allow you to generate a file with all the potentially importable model variables laid out in the appropriate format.

Import Links

Each link is shown in a separate row. If this list is empty, the dialog will open with an empty link, otherwise use the button to add a new link. Click on a row to set up information about the link by editing the items below the list (except for the active checkbox which you click on directly in the row). To remove a link, click on the row you want to remove, and then click on the button.

Valid

This column indicates whether the data source you've specified exists and can be read. It will say No until you select a source, and will also say No if you have an existing link, but the file is missing or unreadable.

Active

Check this option to enable the link for Import All on this dialog, and for automatic import if Dynamic is selected. If this is not checked only the import button at the right will cause data to be imported.

Source

This specifies the file from which the software will read the data. Click on the Browse button to open a File Selection dialog and choose a file. If the file can't be used, most commonly because all its worksheets are already specified for importing or exporting data, an error message will appear.

Note: The file should be located in the same directory as the model, or a subdirectory of the model directory, named data. If you use a file from a different location, copying the model to a different computer will likely make the link invalid.

Worksheet

This option is only applicable to Excel files. After you've selected the file, the first available worksheet it contains will be shown. Click on the dropdown to select the sheet you want..

Note: You can only choose worksheets not already in use by other import or export links. If there's a single worksheet available, it will be the only one shown. If all the worksheets are in use you will get a message stating this.

Note If you add a sheet to an Excel workbook with this dialog open, the new sheet may not be recognized. Close and reopen the dialog. If that fails close and reopen Stella.

Note If you are importing data from an Excel file that came from another computer or via email you should first open the file in Excel before asking Stella to operate on it. Otherwise you may get security warnings that cause importing to fail. This is especially true on the Macintosh.

Type/Link Type

Import Behavior

Note When used in calibration the different choices for time varying parameters do not matter, only the actual data points imported are used.

Note You can override the interpolation mode for individual imported variables by following their name by :c for continuous, :i for inside, :e for extrapolated, :b for backward, :f for forward and :r for raw (that is, using var[1,3]:e instead of var[1,3] in the first row or column of the import csv or Excel file).

Import

Click on the button to import from the designated link. The import will be attempted regardless of the Enabled and Dynamic settings. A message will be shown about the success of, or problems with, the import.

Import All

Click this button to import from all of the links that are marked active. This will happen whether the links are marked dynamic or not. A message will be displayed showing the results of all the imports. If you have many links, this is a convenient way to check that they're all working as expected.

OK/Cancel

Click OK to save the changes you've made to links. Click Cancel to discard them. If you've executed any imports, the data from those will still be in your model.

Note: Importing data is not part of the Undo/Redo system. Once you've imported a value, then the associated equation for the constant, or the graphical function's list of points, will be permanently changed for links that overwrite parameters.