// ************************************************************************** // // // // eses eses // // eses eses // // eses eseses esesese eses Embedded Systems Group // // ese ese ese ese ese // // ese eseseses eseseses ese Department of Computer Science // // eses eses ese eses // // eses eseses eseseses eses University of Kaiserslautern // // eses eses // // // // ************************************************************************** // // This example from systems biology is purely continuous. It describes the // // growth of predator and prey populations that are governed by the parameters// // mentioned below. // // ************************************************************************** // macro pred0 = 100.0; // initial population of predators macro prey0 = 10000.0; // initial population of prey macro a = 0.04; // natural growth rate of prey macro b = 0.0005; // prey death rate per encounter with predator macro c = 0.2; // death rate of predator in absence of food macro e = 0.1; // efficiency of turning prey into new predators module Predator() { hybrid real pop_pred,pop_prey; pop_prey = prey0; pop_pred = pred0; pause; flow{ drv(pop_prey) <- cont(a * pop_prey - b * pop_pred * pop_prey); drv(pop_pred) <- cont(e * b * pop_prey * pop_pred - c * pop_pred); } until(false); }