How can I perform a double integration of a generic function?
You can calculate the Area Under Curve (integral) for any model or generic function in a SAAM II Compartmental model by setting the Compute Sample AUC’s option in Computational Settings (see How can I calculate the Area Under the Curve for a generic function?). An alternate method can also be used to calculate an AUC that takes advantage of specific characteristics of the compartmental model itself. By combining the two methods, it’s easy to perform a double integration. This alternate method for computing an AUC uses a compartment and an input as shown in Figure 1. Throughout an experiment, the compartment will accumulate the total amount of material from the input. If the input is a constant infusion of 2.0 throughout an experiment of duration 100.0, for example, the amount of material in the compartment at any time will be 2.0 * t. At the end of the experiment, the total will be 2.0 * 100.0 = 200.0, the AUC of the input function.
