Sun, 26/02/2012 - 00:41 — administrator

ModelId:

ageclass4

SimileVersion:

5.9

This models a population of animals in terms of four age-classes. For each age-class, we use a compartment (state variable) to represent the number of individuals in that class.

In this model, there are four compartments on the model diagram. They are connected by flow arrows, which represent the aging process: the flow of individuals from one class to the next as they get older. Simile allows the same mathematical model to be represented more concisely, using a single compartment embeddedinside a multiple-instance submodel: see the links to other models below.

Equations:

Compartments

pop_size_1: initial value = 2

pop size_2: initial value = 0

pop size_3: initial value = 0

pop size_4: initial value = 0

Flows

ageing_1 = pop_size_1

ageing_2 = 0.2*pop_size_2

ageing_3 = 0.1*pop_size_3

births = births_2+births_3+births_4

deaths_1 = m1*pop_size_1

deaths_2 = m2*pop_size_2

deaths_3 = m3*pop_size_3

deaths_4 = m4*pop_size_4

Parameters

m1 = 0.05

m2 = 0.01

m3 = 0.01

m4 = 0.05

Intermediate variables

births_2 = r2*pop_size_2

births_3 = r3*pop_size_3

births_4 = r4*pop_size_4

pop size = pop_size_1+pop_size_2+pop_size_3+pop_size_4

r2 = 0.05*(1-pop_size/100)

r3 = 0.2*(1-pop_size/100)

Results:

Attachment | Size |
---|---|

ageclass4.sml | 230.82 KB |

ageclass4.shf | 3.57 KB |