Convex or concave hull polygons from spatial points

hull_polygon(occ_pr, hull_type = "convex", concave_distance_lim = 5000,
             verbose = TRUE)

Arguments

occ_pr	SpatialPoints* object containing geographic points to be used to create hull polygons. This spatial object must be projected to a system with the argument "+units=m".
hull_type	(character) type of hull polygons to be created. Available options are: "convex" and "concave". Default = "convex".
concave_distance_lim	(numeric) distance, in meters, to be passed to the length_threshold parameter of the `concaveman` function. Default = 5000. Ignored if `hull_type` is not "concave".
verbose	(logical) whether or not to print messages about the process. Default = TRUE.

Value

A SpatialPolygons object with the hull polygon. If the number of points in occ_pr is 1 or 2 a SpatialPointsDataFrame object is returned.

Examples

# data
data("occ_p", package = "rangemap")

# preparing spatial points
occ <- as.data.frame(unique(occ_p))
WGS84 <- sp::CRS("+init=epsg:4326")
occ_sp <- sp::SpatialPointsDataFrame(coords = occ[, 2:3], data = occ,
                                     proj4string = WGS84)

# reprojecting
LAEA <- LAEA_projection(spatial_object = occ_sp)
occ_pr <- sp::spTransform(occ_sp, LAEA)

# convex hull polygon
cvx_hull <- hull_polygon(occ_pr, hull_type = "convex")
#> Hull type: convex