Closest observation method

\[\hat{Z}(s_0) = Z(s_{closest})\]

vor <- vect(d) |> voronoi(bnd = map)
vor

##  class       : SpatVector 
##  geometry    : polygons 
##  dimensions  : 575, 7  (geometries, attributes)
##  extent      : 472365.2, 481469.4, 4199888, 4209186  (xmin, xmax, ymin, ymax)
##  coord. ref. : GGRS87 / Greek Grid (EPSG:2100) 
##  names       :    id  size  price prpsqm   age dist_metro  vble
##  type        : <chr> <int>  <int>  <num> <num>      <num> <num>
##  values      :  1935    62  79000   1274     8      586.2  1274
##                 1460    92 115000   1250    13      692.1  1250
##                 1509    82 200000   2439    12      593.3  2439