You specify the contents of an input field in a properties dialog in one of three ways:
•You type in a number;
•You create a link to another element by entering the name of an output of that element; or
•You enter a mathematical expression, such as 3*log(250). Note that the expression itself can incorporate links (the names of element outputs), such as A*log(B), where A and B are output names.
Examples of all three of these types of inputs are shown below: