```
# NOT RUN {
xy <- cbind.data.frame(x = runif(200,-1,1), y = runif(200,-1,1))
posi <- factor(xy$x > 0) : factor(xy$y > 0)
coul <- c("black", "red", "green", "blue")
if(adegraphicsLoaded()) {
s.class(xy, posi, ppoi.cex = 1.5, chullSize = c(0.25, 0.5, 0.75, 1), ellipseSize = 0,
starSize = 0, ppoly = list(col = "white", border = coul))
} else {
s.chull(xy, posi, cpoi = 1.5, col = coul)
}
# }
```

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