rSSI2: An implementation of a Simple Sequential Inhibition (SSI)...

In dschlaep/ecotoner: ecotoner - ecotones / ecological boundaries across environmental gradients

Description

rSSI of cell-center points and avoiding spatstat. This function generates a random pattern of points selected from win all of which have at least r units distance to each other.

Usage

rSSI2(r, n, win, giveup = 1000, x.init = NULL, ...)

Arguments

r	Inhibition distance.
n	Maximum number of points allowed. If n is finite, stop when the total number of points in the point pattern reaches n. If n is infinite (the default), stop only when it is apparently impossible to add any more points. See Details.
win	Window in which to simulate the pattern. An object of class "owin" or something acceptable to as.owin. The default window is the unit square, unless x.init is specified, when the default window is the window of x.init.
giveup	Number of rejected proposals after which the algorithm should terminate.
x.init	Optional. Initial configuration of points. A point pattern (object of class "ppp"). The pattern returned by rSSI consists of this pattern together with the points added via simple sequential inhibition. See Details.
...	Ignored.

Details

This function implements the same process as spatstat::rSSI. spatstat::rSSI relies on win being of class owin, produces an object of class ppp - both very memory-intensive classes -, and copies such objects excessively. For instance, a matrix with 75 million rows (1.1 GB memory) was translated into an object of class owin of 16.8 GB memory usage. Running spatstat::rSSI on this 'owin' object failed after the process required more than than 84 GB memory - more than was available.

See Also

spatstat::rSSI which this function simplifies

dschlaep/ecotoner documentation built on May 15, 2019, 2:57 p.m.