R/rMaternII.sp2.R

In baddstats/spherstat: Spatial Point Pattern Analysis, Geometry and Trigonometry for the Sphere

rMaternII.sp2 <- function(kappa, r, win=sphwin(type="sphere")) {
	X1 <- rpoispp.sp2(lambda=kappa, win=win)
	nrX <- nrow(X1$X)
	X2 <- runif.sphwin(n=1, win=win)
	for(i in 1:(nrX-1)) {
		Xtest <- runif.sphwin(n=1, win=win)
		to.keep <- c()
		nrX2 <- nrow(X2$X)
		if(length(X2$X)==0) {
			## cat("0 ")
			X2$X <- rbind(X2$X, Xtest)
		}
		else {
			for(j in 1:nrX2) {
				if(gcdist(Xtest$X, matrix(X2$X[j,], nrow=1, ncol=2, byrow=TRUE)) > r) {
					to.keep <- c(to.keep, j)
				}
			}
			if(length(to.keep) == nrX2) {
				X2$X <- rbind(X2$X, Xtest$X)
			}
			else {
				X2$X <- X2$X[to.keep,]
			}
		}
	}
	X2
}