Setting Project Variables

A variable is a numerical value, mathematical expression, or mathematical function that can be assigned to a design parameter. You can assign a variable to any dimension, material property, or output value in SI Xplorer. Variables are useful if you expect to change a parameter often, or expect to use the same parameter value often.

Access project variables in SI Xplorer by clicking Project > Project Variables.

The Properties window appears, on the Project Variables tab:

Adding Project Variables

1. From the Project Variables tab, click Add.

   The Add Property dialog box appears.

   

2. Enter information for the variable, as applicable:
   • Name – project variable names must start with the dollar sign symbol ($), followed by a letter. The name can contain alphanumeric characters and underscores (_).
   • Variable Type – use the Variable and Separatorradio buttons to select the variable type.

     Your selection impacts which properties you can edit:

     Variable Type	Editable Properties
     Variable	Unit Type, Units, Value.
     Separator	Name only. A separator variable provides a bolded name for a blank line to facilitate grouping variables in variable lists.

   • Unit Type – for Variables, use the drop-down menu to select a type from the list (e.g., Charge, Density, Energy, et cetera). “None” is the default.

     When you select a Unit Type, the choices in drop-down menu for the Units text box adapt to that unit type. For example, selecting Length as the Unit Type causes the Unit menu to show a range of metric and english units for length. Similarly, if you select the Unit Type as Resistance, the Units drop down lists a range of standard Ohm units.

   • Units – for Variables, use the drop-down menu to select a unit of measure.
   • Value – for Variables, enter a number, variable, or mathematical expression. The quantity entered will be the current (or default) value for the variable. If the mathematical expression includes a reference to an existing variable, this variable is treated as a dependent variable. The units for a dependent variable will automatically change to those of the independent variable on which the value depends.
     Warning:

     If you include the variable's units in its definition (in the Value text box), do not include the variable's units when you enter the variable name for a parameter value.

3. Click OK.

   The new variable appears in the list. You can sort project variables by clicking the Name column header. Clicking once sorts them in ascending order, noted by a triangle pointing up. Clicking against sorts in descending order, noted by a triangle pointing down. Clicking a third time sorts in original order, with no triangle.

4. If appropriate, use the check boxes to designate a variable as Read-only or Hidden.
   • Read-only – when selected, the variable's name, value, unit, and description cannot be modified.
   • Hidden – hidden variables do not appear in the Properties window unless Show Hidden is selected.
5. Click Apply to apply changes.
6. Click OK to exit the window.

Editing Project Variables

To edit a project variable:

1. Access Project Variables.
2. Select the variable you want to edit and click Edit.
3. Change the properties as appropriate and click OK.

Removing Project Variables

To remove a project variable:

1. Access Project Variables.
2. Click Remove.

   A drop-down menu appears.

   

3. Remove one or more variables:
   • To remove a specific variable, ensure it is selected and click  Remove Selected.
   • To remove all unused variables, click  Remove All Unused.
   • To force the removal of all unused variables, including those in the project's undo/redo history, click Force Remove All Unused.