SIR {phaseR}

The SIR epidemic model

Description

The derivative function of the SIR epidemic model, an example of a two-dimensional autonomous ODE system.

Usage

SIR(t, y, parameters)

Arguments

t

The value of t, the independent variable, to evaluate the derivative at. Should be a numeric vector of length one.

y

The values of x and y, the dependent variables, to evaluate the derivative at. Should be a numeric vector of length two.

parameters

The values of the parameters of the system. Should be a numeric vector with parameters specified in the following order: β, ν.

Details

SIR evaluates the derivative of the following ODE at the point (t, x, y):

dx/dt = -βxy, dy/dt = βxy - νy.

Its format is designed to be compatible with ode from the deSolve package.

Value

Returns a list containing the values of the two derivatives at (t, x, y).

Author(s)

Michael J Grayling

See Also

ode