HW 5

Population model for HW5.
We all seem to have settled for convenience on 1-year age classes.
It remains to choose death-rates (i.e. fraction of people of age, i,
who die in 1 year) and birth-rates (i.e. average number of offspring
per person of age i in one year) for each age class.
Make a choice: you may use either something simple, but sensible,
off the top of your head, or you may use some actual data for the
US population.

Then choose an initial condition: the population of each age class
at time 0. Just to be specific, let's start with a population like
some strife-torn regions of the world, where there are many young
people and hardly any older ones: let's make it very simple and
suppose 1 unit in each class up to age 20 and 0 units in every other
age class.

Simulate and graph what happens for the next 100 years.

Describe your results in words, drawing attention to - and explaining
if possible - any noteworthy features.

If you are unsure how to proceed, come and see me Monday
during office hours (1-3pm) or email me.

A couple of notes:

(1) Although animation of results is nice for live or web-based presentations, 
for the report destined for paper you should just show all the frames superimposed: by setting
insequence=false in the plots[display] command.

(2) I want to give you a heads up that from HW 6 on, I'm going to enforce the programming
practice of "no data redundancy" by having the grader take
off points for each numerical datum that appears more than
once in a program. For example, if the maximum age in your
HW5 code is 110, you should set
amax:=110
and the number 110 should not appear anywhere else in
your code. As I said in class removes the danger
of mistakenly having different maximum ages in
different parts of the code, and also allows you
to change the maximum age very easily if you decide
you want to.