rsyst
Simulate systematic random point pattern
Generates a
Usage
rsyst(win=square(1), nx=NULL, ny=nx, ..., dx=NULL, dy=dx)
Arguments
- win
- A window.
An object of class
owin
, or data in any format acceptable toas.owin()
. - nx
- Number of columns of grid points in the window.
Incompatible with
dx
. - ny
- Number of rows of grid points in the window.
Incompatible with
dy
. - ...
- Ignored.
- dx
- Spacing of grid points in $x$ direction.
Incompatible with
nx
. - dy
- Spacing of grid points in $y$ direction.
Incompatible with
ny
.
Details
This function generates a win
. The pattern consists of a
rectangular grid of points with a random common displacement.
The grid spacing in the $x$ direction is determined
either by the number of columns nx
or by the
horizontal spacing dx
.
The grid spacing in the $y$ direction is determined
either by the number of rows ny
or by the
vertical spacing dy
.
The grid is then given a random displacement (the common displacement
of the grid points is a uniformly distributed random vector in the
tile of dimensions dx, dy
).
Some of the resulting grid points may lie outside the window
win
: if they do, they are deleted. The result is a point
pattern inside the window win
.
This function is useful in creating dummy points for quadrature
schemes (see quadscheme
) as well as in simulating
random point patterns.
Value
- A point pattern (object of class
"ppp"
).
See Also
Examples
X <- rsyst(nx=10)
plot(X)
# polygonal boundary
data(letterR)
X <- rsyst(letterR, 5, 10)
plot(X)