WOLFRAM SYSTEM MODELER

Flu

Model of an influenza epidemic

Diagram

Wolfram Language

In[1]:=
SystemModel["SystemDynamics.IntroductoryExamples.Influenza.Flu"]
Out[1]:=

Information

The influenza model describes the outbreak of an influenza epidemic. The model was adapted from the STELLA manual.


References:

  1. Richmond, B., S. Peterson, and P. Vescuso (1987), An Academic User's Guide to STELLA, High Performance Systems, Inc., Lyme, N.H.


Simulate the model across 52 time units and plot the four populations:

Outputs (4)

Non_inf_pop

Type: Real

Description: Non-infected population

Inf_pop

Type: Real

Description: Infected population

Sick_pop

Type: Real

Description: Sick population

Immune_pop

Type: Real

Description: Immune population

Components (21)

Non_infected

Type: Level

Description: General System Dynamics level

Infection

Type: Rate_1

Description: Unrestricted rate element with one influencing variable

Infected

Type: Level

Description: General System Dynamics level

Incubation

Type: Rate_1

Description: Unrestricted rate element with one influencing variable

Sick

Type: Level

Description: General System Dynamics level

Infection_Rate1

Type: Infection_Rate

Description: Non-linear infection rate model

Prod_4_1

Type: Prod_4

Description: Product of four influencing factors

Contacts

Type: Const

Description: A constant factor

Contraction

Type: Const

Description: A constant factor

Incubation_rate

Type: Rate_equation

Description: Non-linear function describing the rate equations

Time_to_Breakdown

Type: Const

Description: A constant factor

Contagious

Type: Add

Description: Output the sum of the two inputs

Perc_Infected

Type: Division

Description: Output first input divided by second input

Total_Pop

Type: Add3

Description: Output the sum of the three inputs

Immune

Type: Level

Description: General System Dynamics level

Cure

Type: Rate_1

Description: Unrestricted rate element with one influencing variable

Cure_rate

Type: Rate_equation

Description: Non-linear function describing the rate equations

Sick_Duration

Type: Const

Description: A constant factor

Immune_Period

Type: Const

Description: A constant factor

Activation

Type: Rate_1

Description: Unrestricted rate element with one influencing variable

Activation_rate

Type: Rate_equation

Description: Non-linear function describing the rate equations