# Defining Variables

## Defining Continuous Variables

Define continuous variables to perform optimization. You cannot perform an Evaluation Design Study using continuous variables. A continuous variable is one which has any value (whole, rational, and irrational) between the minimum and the maximum values. For example, 2.131567 is a valid value between a minimum value of 2 and a maximum value of 5.

1. On the Variable View tab of the design study, in Variables section, do one of the following:
• Select a predefined parameter from the list.
• Select Add Parameter, define a parameter, and select the newly defined parameter from the list.
The parameter name appears in the Variables section.
2. For the variable name, select Range.
You must select Range to define continuous variables. You cannot use the Range with Step and Discrete Values options.
3. For Min, type the minimum value of the continuous variable, for example 11mm or 2 N/m2 . For Max, type the maximum value of the continuous variable.
4. Repeat steps 1 and 2 to define additional continuous variables.

## Defining Discrete Variables Using Variable View

Set discrete variables to evaluate scenarios or perform optimization. If you perform optimization with discrete variables only, the program selects the optimal solution from one of the defined scenarios. A discrete variable is defined by a specific value. For example, 3,4,4.2,5 represents a set of discrete values.

1. On the Variable View tab of the design study, in Variables section, do one of the following:
• Select a predefined parameter from the list.
• Select Add Parameter, define a parameter, and select the newly defined parameter from the list.
The parameter name appears in the Variables section.
2. For the variable name, do one of the following:
• Select Range with Step. For Min, type the minimum value of the variable. For Max, type the maximum value of the variable. For Step, type the value of the step size. For example, if Min is 10mm, Max is 20mm, and Step is 5mm, the program selects 10mm, 15mm, and 20mm as the variable values.
• Select Discrete Values, then type each value and its units. Use a comma to separate the values, for example, 2mm,3mm,4mm.
3. Repeat steps 1 and 2 to define additional discrete variables.

## Defining Discrete Variables Using Table View

Set discrete variables using table view to define each scenario manually. If you perform optimization with discrete variables only, the program finds the optimal scenario only from the list of defined scenarios.

1. On the Table View tab of a design study, in Variables section, do one of the following:
• Select a predefined parameter from the list.
• Select Add Parameter, define a parameter, and select the newly defined parameter from the list.
The parameter name appears in the Variables section.
2. For the variable name, select Enter Value and type the value for Scenario 1.
3. Define an additional scenario by selecting the check box in the column of the previous scenario. Type the values of variables for the additional scenario.

The figure shows the check box you select to define an additional scenario. 4. Repeat steps 1 through 3 to define additional discrete variables.