PROCESSES THAT CHANGE WITH TIME: INTRODUCTION TO DYNAMICAL SYSTEMS - An Invitation to Biomathematics - page 49

Notice that this model is recursive; knowing the ''present value'' p n 1 ,we
can determine the ''next value'' p n . This is exactly the syntax used in
BERKELEY MADONNA to describe the equations.
Enter the following (the first line is the default and we have specified
appropriate values for STARTTIME, STOPTIME, and DT):
METHOD RK4
STARTTIME ¼ 0
STOPTIME ¼ 10
DT ¼ 1
init p ¼ 5.3
next p ¼ (1 þ k)*p
k ¼ 0.345
Run the model to obtain the graph and a table of values for the
population size p (see Figure 1-28). Pressing the Data Points button
(an icon with a solid black dot located across from the Run button) will
show you the points on the graph that make the numerical solution table
for p.
FIGURE 1-28.
BERKELEY MADONNA graphical output depicting the data points representing the numerical solution.