1. Double Variable A double variable is used to parameterize a decimal number in the model. The variable can be referenced from model properties and varied across conditions in parameter studies. Value: The default value of the variable (decimal number). Unit: The unit of the variable (default: "-"). You can assign a double variable to a double precision field by using the Set script pop-up menu item or clicking Ctrl+2 in the field. In the condition editor you can assign values to this double variable. See Variables and Scripting for more information on how to use variables.