Extent of occurrence of a species based on convex hull polygons

Extent of occurrence of a species based on convex hull polygons

eoo(occurrences, polygons)

Arguments

occurrences	a data.frame containing geographic coordinates of species occurrences, columns must be: Species, Longitude, and Latitude. Geographic coordinates must be in decimal degrees (WGS84).
polygons	SpatialPolygons object to clip convex hulls to these limits. Projection must be WGS84 (EPSG:4326).

Value

A list containing a SpatialPolygonsDataFrame of the extent of occurrence, and a vector with the areas in km2 of the spatial polygons resulted. Projection of resulting spatial object is Lambert Azimuthal Equal Area.

Details

Areas are calculated in square kilometers using the Lambert Azimuthal Equal Area projection, centered on the centroid of occurrence points given as inputs.

Examples

# occurrences
data("occ_f", package = "rangemap")
occ <- unique(occ_f)

# polygons
poly <- simple_wmap("simple", "Cuba")
LAEA <- LAEA_projection(occ[, 2:3])
poly_pr <- sp::spTransform(poly, LAEA)

# to fix topology problems
poly_pr <- rgeos::gBuffer(poly_pr, width = 0)

# EOO
eoo_pe <- eoo(occurrences = occ, polygons = poly_pr)