First Parameter

In this basic-level tutorial, we will create a parameter definition, and add a parameter value to an entity. This tutorial is based on First Entity Class And Entity. If you have completed the tutorial previously, start Spine Toolbox, select File -> New DB Editor to open the Database editor. Then, click the Open icon on the toolbar or select File->Open… to open the database you used for the tutorial.

Adding Parameter Definitions

Let’s define a parameter for Fish. Press Alt+Shift+3 or click the Parameter definition tab to bring the Parameter definition dock into focus. The dock contains two tables: The top one is currently empty, but usually it shows existing parameters. You can view current parameters as well as modify them here. The bottom one is called empty table and it is used to add new parameters.

Select Fish from the Entity tree. This will fill the class column in Parameter definition dock with the correct data. Write speed into the parameter name column. Upon pressing Enter, the empty row gets accepted as a proper parameter definition and the row from the empty table is moved to the top table.

In addition to filling the empty rows by hand, it is possible to copy-paste data from a spreadsheet to the empty table.

Adding Parameter Values

Above, we defined a speed parameter for Fish, and now we will set it for Nemo. Press Alt+3 to focus on the Parameter value dock or click the name of its tab. The dock should feel familiar. Indeed, it works much like the Parameter definition dock. Select Nemo from the Entity tree. You may need to expand the fish class with the small arrow on the left first. This will fill the class and entity byname columns of the parameter value table with correct values.

What is a byname, anyway? In case of zero-dimensional entities, like Nemo, it is just the name of the entity. In other tutorials, we will create multidimensional entities, i.e. relationships. In that case, entity byname is a list of the names of the zero-dimensional parts of the relationship.

Let’s get back to parameter values.

Double-click the cell under the parameter name column on the empty row in Parameter value dock. This opens a list of available parameters in the Fish class. Select speed from the list by pressing the Down arrow and hit Tab to move to the next column. You can also select speed by mouse.

The alternative column works the same way as parameter name: editing a cell opens a list of available alternatives. Currently, the only option is Base which readily exists in every freshly created Spine database.

We will discuss alternatives in more depth in other tutorials. For now, it is enough to say that alternatives allow different values for the same parameter, creating a basis for scenarios.

Select Base with the arrow keys and move on to the next column using Tab.

The last column, value, contains the actual speed of Nemo (in the Base alternative). Enter 5 and press Enter to accept the row. A new row containing the added value should now appear on the table above the empty row while the empty row gets cleared. Congratulations, you have just created a parameter value!

Committing Changes

This is a good point to save the changes by committing them. If you are not sure how to do that, visit Committing Changes.

Next Steps

The tutorial continues on First Relationship where we will expand the set of entity classes and entities into multiple dimensions. See you there!