# 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 to`as.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)
```

*Documentation reproduced from package spatstat, version 1.36-0, License: GPL (>= 2)*