| rstrat {spatstat} | R Documentation |
Generates a ``stratified random'' pattern of points in a window,
by dividing the window into rectangular tiles and placing
k random points independently in each tile.
rstrat(win=square(1), nx, ny=nx, k = 1)
win |
A window.
An object of class owin,
or data in any format acceptable to as.owin().
|
nx |
Number of tiles in each column. |
ny |
Number of tiles in each row. |
k |
Number of random points to generate in each tile. |
This function generates a random pattern of points in a ``stratified random'' sampling design. It can be useful for generating random spatial sampling points.
The bounding rectangle of win is divided into
a regular nx * ny grid of rectangular tiles.
In each tile, k random points are generated independently
with a uniform distribution in that tile.
Some of these 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.
A point pattern (object of class "ppp").
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
X <- rstrat(nx=10) plot(X) # polygonal boundary data(letterR) X <- rstrat(letterR, 5, 10, k=3) plot(X)