Extracts Environmental Variables for Occurrences — extract_occurrence

This function extracts values from environmental or predictor variables (SpatRaster) for georeferenced occurrence points. It also adds a column indicating that these are presence points(pr_bg = 1).

Usage

extract_occurrence_variables(occ, x, y, raster_variables)

Arguments

occ: A data.frame containing occurrence data. It must include columns with longitude (x) and latitude (y) coordinates.
x: (character) a string specifying the name of the column in occ that contains the longitude values.
y: (character) a string specifying the name of the column in occ that contains the latitude values.
raster_variables: (SpatRaster) predictor variables used to calibrate the models.

Value

A data.frame containing the original x and y coordinates of the occurrence points (x and y), the values of the variables extracted from raster_variables, and a new column pr_bg with a value of 1 for all occurrences.

Examples

# Import occurrences
data(occ_data, package = "kuenm2")

# Import raster layers
var <- terra::rast(system.file("extdata", "Current_variables.tif",
                               package = "kuenm2"))

# Extracts environmental variables for occurrences
occ_var <- extract_occurrence_variables(occ = occ_data, x = "x", y = "y",
                                        raster_variables = var)