circleHull: Circle hull model In rspatial/dismo: Species Distribution Modeling

Description

The Circle hull model predicts that a species is present at sites inside the smallest circle that can contain a set of training points, and absent outside that circle.

Usage

 `1` ```circleHull(p, ...) ```

Arguments

 `p` point locations (presence). Two column matrix, data.frame or SpatialPoints* object `...` Additional arguments. See details

Value

An object of class 'CircleHull' (inherits from `DistModel-class`)

Author(s)

Robert J. Hijmans

`circles, convHull, rectHull, predict`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23``` ```r <- raster(system.file("external/rlogo.grd", package="raster")) #presence data pts <- matrix(c(17, 42, 85, 70, 19, 53, 26, 84, 84, 46, 48, 85, 4, 95, 48, 54, 66, 74, 50, 48, 28, 73, 38, 56, 43, 29, 63, 22, 46, 45, 7, 60, 46, 34, 14, 51, 70, 31, 39, 26), ncol=2) train <- pts[1:12, ] test <- pts[13:20, ] ch <- circleHull(train) predict(ch, test) plot(r) plot(ch, border='red', lwd=2, add=TRUE) points(train, col='red', pch=20, cex=2) points(test, col='black', pch=20, cex=2) pr <- predict(ch, r, progress='') plot(pr) points(test, col='black', pch=20, cex=2) points(train, col='red', pch=20, cex=2) # to get the polygons: p <- polygons(ch) p ```