sim.pointSource {surveillance} | R Documentation |
Generation of Simulated Point Source Epidemy
Description
Simulation of epidemies which were introduced by point sources.
The basis of this proagramme is a combination of a Hidden Markov Modell
(to get random timepoints for outbreaks) and a simple model
(compare sim.seasonalNoise
) to simulate the epidemy.
Usage
sim.pointSource(p = 0.99, r = 0.01, length = 400, A = 1,
alpha = 1, beta = 0, phi = 0, frequency = 1, state = NULL, K)
Arguments
p |
probability to get a new epidemy at time i if there was one at time i-1, default 0.99. |
r |
probability to get no new epidemy at time i if there was none at time i-1, default 0.01. |
length |
number of weeks to model, default 400. length is ignored if state
is given. In this case the length of state is used. |
A |
amplitude (range of sinus), default = 1. |
alpha |
parameter to move along the y-axis (negative values not allowed)
with alpha > = A, default = 1. |
beta |
regression coefficient, default = 0. |
phi |
factor to create seasonal moves
(moves the curve along the x-axis), default = 0. |
frequency |
factor to determine the oscillation-frequency, default = 1. |
state |
use a state chain to define the status at this timepoint (outbreak or not).
If not given a Markov chain is generated by the programme, default NULL. |
K |
additional weigth for an outbreak which influences the distribution
parameter mu, default = 0. |
Value
disProg |
a object disProg (disease progress) including a list of the observed, the state chain
and nearly all input parameters.
|
Author(s)
M. Höhle, A. Riebler, C. Lang
See Also
sim.seasonalNoise
Examples
# Plotting of simulated data
disProgObj <- sim.pointSource(p = 0.99, r = 0.5, length = 208,
A = 1, alpha = 1, beta = 0, phi = 0,
frequency = 1, state = NULL, K = 2)
# plot the simulated disease with the defined outbreaks
plot(disProgObj)
state <- rep(c(0,0,0,0,0,0,0,0,1,1), 20)
disProgObj <- sim.pointSource(state = state, K = 1.2)
plot(disProgObj)
[Package
surveillance version 1.0-3
Index]