https://github.com/cran/simecol
Tip revision: 5b1552157acaf4d9ea169a6ac95857afb8f79454 authored by Thomas Petzoldt on 14 April 2011, 00:00:00 UTC
version 0.8
version 0.8
Tip revision: 5b15521
initialize-methods.Rd
\name{initialize-methods}
\docType{methods}
\alias{initialize-methods}
%\alias{initialize}
\alias{initialize,simObj-method}
\title{Methods for Function `initialize' in Package `simecol'}
\description{
This function is used to initialize objects derived from the
\code{simObj} superclass, it is by default automatically called during
object creation and by \code{sim}.
}
\usage{
\S4method{initialize}{simObj}(.Object, \dots)
}
\arguments{
\item{.Object}{\code{simObj} instance which is to be
re-initialized.
}
\item{\dots}{provided for compatibility with the default method of
\code{initialize}, or slots of the object which is to be created (in
case of \code{\link[methods]{new}}).
}
}
\section{Methods}{
\describe{
\item{.Object = "ANY"}{Generic function: see \code{\link[methods]{new}}.}
\item{.Object = "simObj"}{
The \code{initialize} function is normally called implicitly by
\code{new} to create new objects. It may also be called explicitly
to return a cloned and re-initialized object.
The \pkg{simecol} version of \code{initialize} provides an
additonal mechanism to call a user specified function provided in
the \code{initfun} slot of a \code{simObj} instance that can
perform computations during the object creation process. The
\code{initfunc} must have \code{obj} as its only argument and must
return the modified version of this \code{obj}, see examples
below. As a side effect end to ensure consistency,
\code{initialize} clears outputs stored in slot \code{out} from
former simulations.
}
}
}
\seealso{
\code{\link{simObj}}, \code{\link[methods]{new}}
}
\examples{
## Note: new calls initialize and initialize calls initfunc(obj)
lv_efr <- new("odeModel",
main = function (time, init, parms, ...) {
x <- init
p <- parms
S <- approxTime1(inputs, time, rule=2)["s.in"]
dx1 <- S * p["k1"] * x[1] - p["k2"] * x[1] * x[2]
dx2 <- - p["k3"] * x[2] + p["k2"] * x[1] * x[2]
list(c(dx1, dx2))
},
parms = c(k1=0.2, k2=0.2, k3=0.2),
times = c(from=0, to=100, by=0.5),
init = c(prey=0.5, predator=1),
solver = "lsoda",
initfunc = function(obj) {
tt <- fromtoby(times(obj))
inputs(obj) <- as.matrix(data.frame(
time = tt,
s.in = pmax(rnorm(tt, mean=1, sd=0.5), 0)
))
obj
}
)
plot(sim(lv_efr)) # initialize called automatically
plot(sim(lv_efr)) # automatic initialization, different figure
lv_efr<- initialize(lv_efr) # re-initialize manually
plot(sim(lv_efr, initialize = FALSE)) # simulation with that configuration
}
\keyword{methods}