Define Formula

To access this screen:

This screen is accessed from multiple functions in your application.

The Define Formula screen is used to construct a formula that is used in place of an explicit value at some point in the optimization workflow.

Formula arguments vary; for economic settings they define element grades, yet for custom report fields the arguments are standard economic model fields.

Purposes vary too. For example, you may want to modify a product recovery cost by a fixed factor, or a factor based on the grade of the product, or you need to define a delayed recovery cost that is influenced by a product price that varies by a fixed amount over time.

Formulae can include one or more 'arguments' represented by fixed values or variables, where variables can be system or custom (that is, ones you have defined elsewhere previously).

Note: Formulae set using this screen can be sensitive to your operating system locale settings. Formulae may not work as expected if the decimal symbol is set to comma (,) rather than period (.).

The screen comprises the following key areas:

Left pane – Lists the variables available to build a formula. This list will contain any custom variables that have been defined previously.
Right pane – This area is used to build the formula. The formula always starts with "=". The best way to remember this is "my formula equals..." followed by a formula expression.
Check Formula – It is important that formulae adhere to an expected syntax, or downstream calculations can be inaccurate or even fail to complete. This function is used to check the validity of the formula. If the formula is invalid, a message displays "Incorrect formula". See Formula Syntax.

Note: This check is also performed when you click OK.