rMaternII {spatstat} | R Documentation |
Generate a random point pattern, a simulated realisation of the Mat\'ern Model II inhibition process.
rMaternII(kappa, r, win = owin(c(0,1),c(0,1)), stationary=TRUE)
kappa |
Intensity of the Poisson process of proposal points. A single positive number. |
r |
Inhibition distance. |
win |
Window in which to simulate the pattern.
An object of class |
stationary |
Logical. Whether to start with a stationary process of proposal points
( |
This algorithm generates a realisation of Mat\'ern's Model II
inhibition process
inside the window win
.
The process is constructed by first
generating a uniform Poisson point process of “proposal” points
with intensity kappa
. If stationary = TRUE
(the
default), the proposal points are generated in a window larger than
win
that effectively means the proposals are stationary.
If stationary=FALSE
then the proposal points are
only generated inside the window win
.
Then each proposal point is marked by an “arrival time”, a number uniformly distributed in [0,1] independently of other variables.
A proposal point is deleted if it lies within r
units' distance
of another proposal point that has an earlier arrival time.
Otherwise it is retained.
The retained points constitute Mat\'ern's Model II.
The difference between Mat\'ern's Model I and II is the italicised statement above. Model II has a higher intensity for the same parameter values.
The simulated point pattern (an object of class "ppp"
).
Adrian Baddeley Adrian.Baddeley@csiro.au http://www.maths.uwa.edu.au/~adrian/, Ute Hahn, and Rolf Turner r.turner@auckland.ac.nz
X <- rMaternII(20, 0.05) Y <- rMaternII(20, 0.05, stationary=FALSE)