Starting with object generation 2.86, the list of integral quantities may contain objects of type 'Function of int. quant.'. These objects are used in cases where you want to compute functions of other integral quantities, such as differences, sums or ratios.

If you edit an object of type 'Function of int. quant.' you are guided through the sequence of dialogs to set the nickname, unit, scaling factor and decimals. Finally a dialog to set the function is displayed:

In this dialog you can refer to other integral quantities by the symbol iq(index). In the example, iq(1) refers to the first item of the list of integral quantities whereas iq(2) denotes the second item. You can refer to optical functions as well, using the symbol of(index). of(4), for example, refers to the 4th item of the list of optical functions.

The assignment of a spectrum to objects of type 'Function of int. quant.' is completely ignored in the computation.

Note that the order of integral quantities is important if you use functions of integral quantities: The computational routine in CODE computes the items of the integral quantity list from the top to the bottom. Functions that refer to items of this list should be placed underneath all the objects that are required for the computation. In the example above the function object may occur as the third item in the list or below.