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Model : ageclass4
Simile version : 3.1+
Date added : 20030620
Keywords :
Ageclass modelling ;
Population dynamics ;
This models a population of animals in terms of four ageclasses. For each ageclass, 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 multipleinstance submodel: see the links to other models below.
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ageclass4.sml 
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*(1pop_size/100) r3 = 0.2*(1pop_size/100) r4 = 0.1*(1pop_size/100)

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