Voronoi Data Linkage - Single variable and variance

Reminder, have to create an example. This will be exported after we submit the paper for publication.

Usage

vdl_var(coords_sf, areal_sf, res_var, variance, var_method = "CS", buff)

coords_sf: sf POINT target dataset.
areal_sf: sf POLYGON source dataset.
res_var: a character - the name of the variable in the areal_sf to be estimated in the coords_sf.
variance: a character - the name of the variable variance in the areal_sf to be estimated in the coords_sf.
var_method: a character representing the method to approximate the variance of the AI estimates. Possible values are "CS" (Cauchy-Schwartz) or "MI" (Moran's I).
buff: scalar numeric. Mostly for internal use.

a sf object, containing the id_coords variable and the list_vars for the coords_sf spatial data set.