[R-sig-Geo] random points

[adrian at maths.uwa.edu.au]

Rodrigo W. Soria Auza <wilbersa at armonia-bo.org> writes:

> I'm trying to generate a surface of 'random points' over a defined area.
> By 'randon points' I mean points that are not closer than one km each
> other. I used runifpoints (from spatstat). however, this function
> generates strictly random points, with some of them much closer than I
> expected.

In the spatstat package you have several options:

     rstrat: divides the region into squares and places one random point
             in each square (or k random points)

     rsyst:  makes a square grid of points and gives it a random displacement

     rSSI:  places points at random, one-at-a-time,
            each new point being constrained to lie at least r units away
            from the previously existing points

     rStrauss (with gamma=0): places points at random subject to the
            condition that no two points lie closer than r units apart

If you need something more complicated that that, you could try the
package 'spsample'



Adrian Baddeley