simulate.ppm {spatstat.model} | R Documentation |
Simulate a Fitted Gibbs Point Process Model
Description
Generates simulated realisations from a fitted Gibbs or Poisson point process model.
Usage
## S3 method for class 'ppm'
simulate(object, nsim=1, ...,
singlerun = FALSE,
start = NULL,
control = default.rmhcontrol(object, w=w),
w = window,
window = NULL,
project=TRUE, new.coef=NULL,
verbose=FALSE, progress=(nsim > 1),
drop=FALSE)
Arguments
object |
Fitted point process model.
An object of class |
nsim |
Number of simulated realisations. |
singlerun |
Logical. Whether to generate the simulated realisations
from a single long run of the Metropolis-Hastings algorithm
( |
start |
Data determining the initial state
of the Metropolis-Hastings algorithm. See
|
control |
Data controlling the running of
the Metropolis-Hastings algorithm. See |
w , window |
Optional. The window in which the model is defined.
An object of class |
... |
Further arguments passed to |
project |
Logical flag indicating what to do if the fitted model is
invalid (in the sense that the values of the fitted coefficients do not
specify a valid point process).
If |
verbose |
Logical flag indicating whether to print progress reports
from |
progress |
Logical flag indicating whether to print progress reports for the sequence of simulations. |
new.coef |
New values for the canonical parameters of the model.
A numeric vector of the same length as |
drop |
Logical. If |
Details
This function is a method for the generic function
simulate
for the class "ppm"
of fitted
point process models.
Simulations are performed by rmh.ppm
.
If singlerun=FALSE
(the default), the simulated patterns are
the results of independent runs of the Metropolis-Hastings
algorithm. If singlerun=TRUE
, a single long run of the
algorithm is performed, and the state of the simulation is saved
every nsave
iterations to yield the simulated patterns.
In the case of a single run, the behaviour is controlled
by the parameters nsave,nburn,nrep
. These
are described in rmhcontrol
. They may be passed
in the ...
arguments or included in control
.
It is sufficient to specify two
of the three parameters nsave,nburn,nrep
.
Value
A list of length nsim
containing simulated point patterns
(objects of class "ppp"
).
It also belongs to the class "solist"
, so that it can be
plotted, and the class "timed"
, so that the total computation
time is recorded.
Author(s)
Adrian Baddeley Adrian.Baddeley@curtin.edu.au and Rolf Turner rolfturner@posteo.net
See Also
Examples
fit <- ppm(japanesepines, ~1, Strauss(0.1))
simulate(fit, 2)
simulate(fit, 2, singlerun=TRUE, nsave=1e4, nburn=1e4)