Quick Simulation from an Endemic-Only twinstim
In endemic-only twinstim models, the conditional
intensity is a piecewise constant function independent from the history
of the process. This allows for a much more efficient simulation
algorithm than via Ogata's modified thinning as in the general
simulate.twinstim method.
simEndemicEvents(object, tiles)
| object | an object of class  | 
| tiles | an object inheriting from  | 
Sebastian Meyer
the general simulation method simulate.twinstim
data("imdepi", "imdepifit")
load(system.file("shapes", "districtsD.RData", package="surveillance"))
## Fit an endemic-only twinstim()
m_noepi <- update(imdepifit, epidemic = ~0, siaf = NULL, model = TRUE)
## Simulate events from the above endemic model
set.seed(1)
s1 <- simEndemicEvents(m_noepi, tiles = districtsD)
class(s1)  # just a "SpatialPointsDataFrame"
summary(s1)
plot(s1, col = s1$type, cex = 0.5); plot(imdepi$W, lwd = 2, add = TRUE)
## Not run: 
## the general simulation method takes several seconds
s0 <- simulate(m_noepi, seed = 1, data = imdepi, tiles = districtsD)
class(s0)  # gives a full "simEpidataCS" with several methods applicable
methods(class = "epidataCS")
plot(s0, "time")
plot(s0, "space", points.args = list(pch = 3), lwd = 2)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.