| Library: | spatial |
| See also: | SPPPinit SPPPinitrandom SPPPsetregion SPPPgetregion SPPPkfn SPPPpsim SPPPstrauss SPPPkenvl SPPPkaver |
| Quantlet: | SPPPssi | |
| Description: | simulates a SSI (sequential spatial inhibition) point process. Note that SPPPinit or SPPPsetregion must have been called before to set the domain. To be able to reproduce results, reset the random number generator for point processes by calling SPPPinitrandom first. Note that this quantlet will not return a result if r is too large and if it is impossible to place n points. |
| Usage: | res = SPPPssi(nsim, n, r) | |
| Input: | ||
| nsim | scalar, number of simulations | |
| n | scalar, number of points in the domain | |
| r | scalar, inhibition distance | |
| Output: | ||
| res | list, consisting of components xmat, ymat and type: | |
| res.xmat | n x nsim matrix, x coordinates | |
| res.ymat | n x nsim matrix, y coordinates | |
| res.type | string, "SSI" | |
; loads the spatial statistics library
library("spatial")
; reads a spatial data set
pines = read("pines.dat")
; initializes a point process
pinesobj = SPPPinit(pines, 0, 96, 0, 100, 10)
; resets random number generator
SPPPinitrandom(0)
; simulates 100 SSI point processes(with r = 0.7),
; each consisting of 72 points, in the previously
; determined domain
ppssi = SPPPssi(100, 72, 0.7)
ppssi.xmat[1:3,1:3]
ppssi.ymat[1:3,1:3]
List ppssi consists of x and y coordinates of 100 Strauss point processes, each consisting of 72 points. Contents of _tmp [1,] 1.0709e-06 7.7566 8.5364 [2,] 1.1978 5.9195 1.6666 [3,] 0.034049 0.67031 7.4771 Contents of _tmp [1,] 0.030269 9.6169 0.1943 [2,] 4.2072 0.2853 0.88153 [3,] 2.3159 4.7711 0.9613